chrome/browser/about_flags.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/about_flags.h"
   6
   7 #include <iterator>
   8 #include <map>
   9 #include <set>
  10 #include <utility>
  11
  12 #include "base/command_line.h"
  13 #include "base/memory/singleton.h"
  14 #include "base/metrics/sparse_histogram.h"
  15 #include "base/stl_util.h"
  16 #include "base/strings/string_number_conversions.h"
  17 #include "base/strings/string_util.h"
  18 #include "base/strings/utf_string_conversions.h"
  19 #include "base/values.h"
  20 #include "cc/base/switches.h"
  21 #include "chrome/browser/bookmarks/enhanced_bookmarks_features.h"
  22 #include "chrome/browser/flags_storage.h"
  23 #include "chrome/common/chrome_content_client.h"
  24 #include "chrome/common/chrome_switches.h"
  25 #include "chrome/grit/generated_resources.h"
  26 #include "components/autofill/core/common/autofill_switches.h"
  27 #include "components/cloud_devices/common/cloud_devices_switches.h"
  28 #include "components/metrics/metrics_hashes.h"
  29 #include "components/nacl/common/nacl_switches.h"
  30 #include "components/proximity_auth/switches.h"
  31 #include "components/search/search_switches.h"
  32 #include "content/public/browser/user_metrics.h"
  33 #include "media/base/media_switches.h"
  34 #include "ui/base/l10n/l10n_util.h"
  35 #include "ui/base/ui_base_switches.h"
  36 #include "ui/display/display_switches.h"
  37 #include "ui/events/event_switches.h"
  38 #include "ui/gfx/switches.h"
  39 #include "ui/gl/gl_switches.h"
  40 #include "ui/keyboard/keyboard_switches.h"
  41 #include "ui/native_theme/native_theme_switches.h"
  42 #include "ui/views/views_switches.h"
  43
  44 #if defined(OS_ANDROID)
  45 #include "chrome/common/chrome_version_info.h"
  46 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h"
  47 #include "components/omnibox/omnibox_switches.h"
  48 #else
  49 #include "ui/message_center/message_center_switches.h"
  50 #endif
  51
  52 #if defined(USE_ASH)
  53 #include "ash/ash_switches.h"
  54 #endif
  55
  56 #if defined(OS_CHROMEOS)
  57 #include "chromeos/chromeos_switches.h"
  58 #include "third_party/cros_system_api/switches/chrome_switches.h"
  59 #endif
  60
  61 #if defined(ENABLE_APP_LIST)
  62 #include "ui/app_list/app_list_switches.h"
  63 #endif
  64
  65 #if defined(ENABLE_EXTENSIONS)
  66 #include "extensions/common/switches.h"
  67 #endif
  68
  69 namespace about_flags {
  70
  71 // Macros to simplify specifying the type.
  72 #define SINGLE_VALUE_TYPE_AND_VALUE(command_line_switch, switch_value) \
  73     Experiment::SINGLE_VALUE, \
  74     command_line_switch, switch_value, NULL, NULL, NULL, 0
  75 #define SINGLE_VALUE_TYPE(command_line_switch) \
  76     SINGLE_VALUE_TYPE_AND_VALUE(command_line_switch, "")
  77 #define ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(enable_switch, enable_value, \
  78                                             disable_switch, disable_value) \
  79     Experiment::ENABLE_DISABLE_VALUE, enable_switch, enable_value, \
  80     disable_switch, disable_value, NULL, 3
  81 #define ENABLE_DISABLE_VALUE_TYPE(enable_switch, disable_switch) \
  82     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(enable_switch, "", disable_switch, "")
  83 #define MULTI_VALUE_TYPE(choices) \
  84     Experiment::MULTI_VALUE, NULL, NULL, NULL, NULL, choices, arraysize(choices)
  85
  86 namespace {
  87
  88 // Enumeration of OSs.
  89 enum {
  90   kOsMac = 1 << 0,
  91   kOsWin = 1 << 1,
  92   kOsLinux = 1 << 2,
  93   kOsCrOS = 1 << 3,
  94   kOsAndroid = 1 << 4,
  95   kOsCrOSOwnerOnly = 1 << 5
  96 };
  97
  98 const unsigned kOsAll = kOsMac | kOsWin | kOsLinux | kOsCrOS | kOsAndroid;
  99 const unsigned kOsDesktop = kOsMac | kOsWin | kOsLinux | kOsCrOS;
 100
 101 // Adds a |StringValue| to |list| for each platform where |bitmask| indicates
 102 // whether the experiment is available on that platform.
 103 void AddOsStrings(unsigned bitmask, base::ListValue* list) {
 104   struct {
 105     unsigned bit;
 106     const char* const name;
 107   } kBitsToOs[] = {
 108     {kOsMac, "Mac"},
 109     {kOsWin, "Windows"},
 110     {kOsLinux, "Linux"},
 111     {kOsCrOS, "Chrome OS"},
 112     {kOsAndroid, "Android"},
 113     {kOsCrOSOwnerOnly, "Chrome OS (owner only)"},
 114   };
 115   for (size_t i = 0; i < arraysize(kBitsToOs); ++i) {
 116     if (bitmask & kBitsToOs[i].bit)
 117       list->Append(new base::StringValue(kBitsToOs[i].name));
 118   }
 119 }
 120
 121 // Convert switch constants to proper CommandLine::StringType strings.
 122 base::CommandLine::StringType GetSwitchString(const std::string& flag) {
 123   base::CommandLine cmd_line(base::CommandLine::NO_PROGRAM);
 124   cmd_line.AppendSwitch(flag);
 125   DCHECK_EQ(2U, cmd_line.argv().size());
 126   return cmd_line.argv()[1];
 127 }
 128
 129 // Scoops flags from a command line.
 130 std::set<base::CommandLine::StringType> ExtractFlagsFromCommandLine(
 131     const base::CommandLine& cmdline) {
 132   std::set<base::CommandLine::StringType> flags;
 133   // First do the ones between --flag-switches-begin and --flag-switches-end.
 134   base::CommandLine::StringVector::const_iterator first =
 135       std::find(cmdline.argv().begin(), cmdline.argv().end(),
 136                 GetSwitchString(switches::kFlagSwitchesBegin));
 137   base::CommandLine::StringVector::const_iterator last =
 138       std::find(cmdline.argv().begin(), cmdline.argv().end(),
 139                 GetSwitchString(switches::kFlagSwitchesEnd));
 140   if (first != cmdline.argv().end() && last != cmdline.argv().end())
 141     flags.insert(first + 1, last);
 142 #if defined(OS_CHROMEOS)
 143   // Then add those between --policy-switches-begin and --policy-switches-end.
 144   first = std::find(cmdline.argv().begin(), cmdline.argv().end(),
 145                     GetSwitchString(chromeos::switches::kPolicySwitchesBegin));
 146   last = std::find(cmdline.argv().begin(), cmdline.argv().end(),
 147                    GetSwitchString(chromeos::switches::kPolicySwitchesEnd));
 148   if (first != cmdline.argv().end() && last != cmdline.argv().end())
 149     flags.insert(first + 1, last);
 150 #endif
 151   return flags;
 152 }
 153
 154 const Experiment::Choice kTouchEventsChoices[] = {
 155   { IDS_GENERIC_EXPERIMENT_CHOICE_AUTOMATIC, "", "" },
 156   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
 157     switches::kTouchEvents,
 158     switches::kTouchEventsEnabled },
 159   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 160     switches::kTouchEvents,
 161     switches::kTouchEventsDisabled }
 162 };
 163
 164 #if defined(USE_AURA)
 165 const Experiment::Choice kOverscrollHistoryNavigationChoices[] = {
 166   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED, "", "" },
 167   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 168     switches::kOverscrollHistoryNavigation,
 169     "0" },
 170   { IDS_OVERSCROLL_HISTORY_NAVIGATION_SIMPLE_UI,
 171     switches::kOverscrollHistoryNavigation,
 172     "2" }
 173 };
 174 #endif
 175
 176 #if !defined(DISABLE_NACL)
 177 const Experiment::Choice kNaClDebugMaskChoices[] = {
 178   // Secure shell can be used on ChromeOS for forwarding the TCP port opened by
 179   // debug stub to a remote machine. Since secure shell uses NaCl, we usually
 180   // want to avoid debugging that. The PNaCl translator is also a NaCl module,
 181   // so by default we want to avoid debugging that.
 182   // NOTE: As the default value must be the empty string, the mask excluding
 183   // the PNaCl translator and secure shell is substituted elsewhere.
 184   { IDS_NACL_DEBUG_MASK_CHOICE_EXCLUDE_UTILS_PNACL, "", "" },
 185   { IDS_NACL_DEBUG_MASK_CHOICE_DEBUG_ALL, switches::kNaClDebugMask, "*://*" },
 186   { IDS_NACL_DEBUG_MASK_CHOICE_INCLUDE_DEBUG,
 187       switches::kNaClDebugMask, "*://*/*debug.nmf" }
 188 };
 189 #endif
 190
 191 const Experiment::Choice kMaxTilesForInterestAreaChoices[] = {
 192   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 193   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_SHORT,
 194     cc::switches::kMaxTilesForInterestArea, "64"},
 195   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_TALL,
 196     cc::switches::kMaxTilesForInterestArea, "128"},
 197   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_GRANDE,
 198     cc::switches::kMaxTilesForInterestArea, "256"},
 199   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_VENTI,
 200     cc::switches::kMaxTilesForInterestArea, "512"}
 201 };
 202
 203 const Experiment::Choice kDefaultTileWidthChoices[] = {
 204   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 205   { IDS_FLAGS_DEFAULT_TILE_WIDTH_SHORT,
 206     switches::kDefaultTileWidth, "128"},
 207   { IDS_FLAGS_DEFAULT_TILE_WIDTH_TALL,
 208     switches::kDefaultTileWidth, "256"},
 209   { IDS_FLAGS_DEFAULT_TILE_WIDTH_GRANDE,
 210     switches::kDefaultTileWidth, "512"},
 211   { IDS_FLAGS_DEFAULT_TILE_WIDTH_VENTI,
 212     switches::kDefaultTileWidth, "1024"}
 213 };
 214
 215 const Experiment::Choice kDefaultTileHeightChoices[] = {
 216   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 217   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_SHORT,
 218     switches::kDefaultTileHeight, "128"},
 219   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_TALL,
 220     switches::kDefaultTileHeight, "256"},
 221   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_GRANDE,
 222     switches::kDefaultTileHeight, "512"},
 223   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_VENTI,
 224     switches::kDefaultTileHeight, "1024"}
 225 };
 226
 227 const Experiment::Choice kSimpleCacheBackendChoices[] = {
 228   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 229   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 230     switches::kUseSimpleCacheBackend, "off" },
 231   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
 232     switches::kUseSimpleCacheBackend, "on"}
 233 };
 234
 235 #if defined(USE_AURA)
 236 const Experiment::Choice kTabCaptureUpscaleQualityChoices[] = {
 237   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 238   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_FAST,
 239     switches::kTabCaptureUpscaleQuality, "fast" },
 240   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_GOOD,
 241     switches::kTabCaptureUpscaleQuality, "good" },
 242   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_BEST,
 243     switches::kTabCaptureUpscaleQuality, "best" },
 244 };
 245
 246 const Experiment::Choice kTabCaptureDownscaleQualityChoices[] = {
 247   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 248   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_FAST,
 249     switches::kTabCaptureDownscaleQuality, "fast" },
 250   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_GOOD,
 251     switches::kTabCaptureDownscaleQuality, "good" },
 252   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_BEST,
 253     switches::kTabCaptureDownscaleQuality, "best" },
 254 };
 255 #endif
 256
 257 #if defined(OS_ANDROID)
 258 const Experiment::Choice kZeroSuggestExperimentsChoices[] = {
 259   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 260   { IDS_FLAGS_ZERO_SUGGEST_MOST_VISITED,
 261     switches::kEnableZeroSuggestMostVisited, ""},
 262   { IDS_FLAGS_ZERO_SUGGEST_MOST_VISITED_WITHOUT_SERP,
 263     switches::kEnableZeroSuggestMostVisitedWithoutSerp, ""},
 264   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 265     switches::kDisableZeroSuggest, ""}
 266 };
 267 #endif
 268
 269 const Experiment::Choice kNumRasterThreadsChoices[] = {
 270   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 271   { IDS_FLAGS_NUM_RASTER_THREADS_ONE, switches::kNumRasterThreads, "1" },
 272   { IDS_FLAGS_NUM_RASTER_THREADS_TWO, switches::kNumRasterThreads, "2" },
 273   { IDS_FLAGS_NUM_RASTER_THREADS_THREE, switches::kNumRasterThreads, "3" },
 274   { IDS_FLAGS_NUM_RASTER_THREADS_FOUR, switches::kNumRasterThreads, "4" }
 275 };
 276
 277 const Experiment::Choice kEnableGpuRasterizationChoices[] = {
 278   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 279   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
 280     switches::kEnableGpuRasterization, "" },
 281   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 282     switches::kDisableGpuRasterization, "" },
 283   { IDS_FLAGS_FORCE_GPU_RASTERIZATION,
 284     switches::kForceGpuRasterization, "" },
 285 };
 286
 287 // We're using independent flags here (as opposed to a common flag with
 288 // different values) to be able to enable/disable the entire experience
 289 // associated with this feature server-side from the FieldTrial (the complete
 290 // experience includes other flag changes as well). It is not currently possible
 291 // to do that with "flag=value" flags.
 292 const Experiment::Choice kSearchButtonInOmniboxChoices[] = {
 293   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 294   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 295     switches::kDisableSearchButtonInOmnibox, ""},
 296   { IDS_FLAGS_SEARCH_BUTTON_IN_OMNIBOX_ENABLE_FOR_STR,
 297     switches::kEnableSearchButtonInOmniboxForStr, ""},
 298   { IDS_FLAGS_SEARCH_BUTTON_IN_OMNIBOX_ENABLE_FOR_STR_OR_IIP,
 299     switches::kEnableSearchButtonInOmniboxForStrOrIip, ""},
 300   { IDS_FLAGS_SEARCH_BUTTON_IN_OMNIBOX_ENABLED,
 301     switches::kEnableSearchButtonInOmniboxAlways, ""}
 302 };
 303
 304 // See comment above for kSearchButtonInOmniboxChoices. The same reasoning
 305 // applies here.
 306 const Experiment::Choice kOriginChipChoices[] = {
 307   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 308   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED, switches::kDisableOriginChip, ""},
 309   { IDS_FLAGS_ORIGIN_CHIP_ALWAYS, switches::kEnableOriginChipAlways, ""},
 310   { IDS_FLAGS_ORIGIN_CHIP_ON_SRP, switches::kEnableOriginChipOnSrp, ""}
 311 };
 312
 313 const Experiment::Choice kTouchScrollingModeChoices[] = {
 314   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 315   { IDS_FLAGS_TOUCH_SCROLLING_MODE_TOUCHCANCEL,
 316     switches::kTouchScrollingMode,
 317     switches::kTouchScrollingModeTouchcancel },
 318   { IDS_FLAGS_TOUCH_SCROLLING_MODE_ASYNC_TOUCHMOVE,
 319     switches::kTouchScrollingMode,
 320     switches::kTouchScrollingModeAsyncTouchmove },
 321   { IDS_FLAGS_TOUCH_SCROLLING_MODE_SYNC_TOUCHMOVE,
 322     switches::kTouchScrollingMode,
 323     switches::kTouchScrollingModeSyncTouchmove },
 324 };
 325
 326 const Experiment::Choice kExtensionContentVerificationChoices[] = {
 327   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 328   { IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_BOOTSTRAP,
 329     switches::kExtensionContentVerification,
 330     switches::kExtensionContentVerificationBootstrap },
 331   { IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_ENFORCE,
 332     switches::kExtensionContentVerification,
 333     switches::kExtensionContentVerificationEnforce },
 334   { IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_ENFORCE_STRICT,
 335     switches::kExtensionContentVerification,
 336     switches::kExtensionContentVerificationEnforceStrict },
 337 };
 338
 339 // Note that the value is specified in seconds (where 0 is equivalent to
 340 // disabled).
 341 const Experiment::Choice kRememberCertificateErrorDecisionsChoices[] = {
 342   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 343   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 344     switches::kRememberCertErrorDecisions,
 345     "-1" },
 346   { IDS_REMEMBER_CERTIFICATE_ERROR_DECISION_CHOICE_ONE_DAY,
 347     switches::kRememberCertErrorDecisions,
 348     "86400" },
 349   { IDS_REMEMBER_CERTIFICATE_ERROR_DECISION_CHOICE_THREE_DAYS,
 350     switches::kRememberCertErrorDecisions,
 351     "259200" },
 352   { IDS_REMEMBER_CERTIFICATE_ERROR_DECISION_CHOICE_ONE_WEEK,
 353     switches::kRememberCertErrorDecisions,
 354     "604800" },
 355   { IDS_REMEMBER_CERTIFICATE_ERROR_DECISION_CHOICE_ONE_MONTH,
 356     switches::kRememberCertErrorDecisions,
 357     "2592000" },
 358   { IDS_REMEMBER_CERTIFICATE_ERROR_DECISION_CHOICE_THREE_MONTHS,
 359     switches::kRememberCertErrorDecisions,
 360     "7776000" },
 361 };
 362
 363 const Experiment::Choice kAutofillSyncCredentialChoices[] = {
 364   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", ""},
 365   { IDS_ALLOW_AUTOFILL_SYNC_CREDENTIAL,
 366     password_manager::switches::kAllowAutofillSyncCredential, ""},
 367   { IDS_DISALLOW_AUTOFILL_SYNC_CREDENTIAL_FOR_REAUTH,
 368     password_manager::switches::kDisallowAutofillSyncCredentialForReauth, ""},
 369   { IDS_DISALLOW_AUTOFILL_SYNC_CREDENTIAL,
 370     password_manager::switches::kDisallowAutofillSyncCredential, ""},
 371 };
 372
 373 const Experiment::Choice kSSLVersionMinChoices[] = {
 374   { IDS_FLAGS_SSL_VERSION_DEFAULT, "", "" },
 375   { IDS_FLAGS_SSL_VERSION_SSLV3, switches::kSSLVersionMin,
 376     switches::kSSLVersionSSLv3 },
 377   { IDS_FLAGS_SSL_VERSION_TLSV1, switches::kSSLVersionMin,
 378     switches::kSSLVersionTLSv1 },
 379   { IDS_FLAGS_SSL_VERSION_TLSV11, switches::kSSLVersionMin,
 380     switches::kSSLVersionTLSv11 },
 381   { IDS_FLAGS_SSL_VERSION_TLSV12, switches::kSSLVersionMin,
 382     switches::kSSLVersionTLSv12 },
 383 };
 384
 385 const Experiment::Choice kFillOnAccountSelectChoices[] = {
 386   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
 387   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
 388     autofill::switches::kDisableFillOnAccountSelect, "" },
 389   { IDS_FLAGS_FILL_ON_ACCOUNT_SELECT_ENABLE_HIGHLIGHTING,
 390     autofill::switches::kEnableFillOnAccountSelect, "" },
 391   { IDS_FLAGS_FILL_ON_ACCOUNT_SELECT_ENABLE_NO_HIGHLIGHTING,
 392     autofill::switches::kEnableFillOnAccountSelectNoHighlighting, "" },
 393 };
 394
 395 // RECORDING USER METRICS FOR FLAGS:
 396 // -----------------------------------------------------------------------------
 397 // The first line of the experiment is the internal name. If you'd like to
 398 // gather statistics about the usage of your flag, you should append a marker
 399 // comment to the end of the feature name, like so:
 400 //   "my-special-feature",  // FLAGS:RECORD_UMA
 401 //
 402 // After doing that, run
 403 //   tools/metrics/actions/extract_actions.py
 404 // to add the metric to actions.xml (which will enable UMA to record your
 405 // feature flag), then update the <owner>s and <description> sections. Make sure
 406 // to include the actions.xml file when you upload your code for review!
 407 //
 408 // After your feature has shipped under a flag, you can locate the metrics under
 409 // the action name AboutFlags_internal-action-name. Actions are recorded once
 410 // per startup, so you should divide this number by AboutFlags_StartupTick to
 411 // get a sense of usage. Note that this will not be the same as number of users
 412 // with a given feature enabled because users can quit and relaunch the
 413 // application multiple times over a given time interval. The dashboard also
 414 // shows you how many (metrics reporting) users have enabled the flag over the
 415 // last seven days. However, note that this is not the same as the number of
 416 // users who have the flag enabled, since enabling the flag happens once,
 417 // whereas running with the flag enabled happens until the user flips the flag
 418 // again.
 419
 420 // To add a new experiment add to the end of kExperiments. There are two
 421 // distinct types of experiments:
 422 // . SINGLE_VALUE: experiment is either on or off. Use the SINGLE_VALUE_TYPE
 423 //   macro for this type supplying the command line to the macro.
 424 // . MULTI_VALUE: a list of choices, the first of which should correspond to a
 425 //   deactivated state for this lab (i.e. no command line option).  To specify
 426 //   this type of experiment use the macro MULTI_VALUE_TYPE supplying it the
 427 //   array of choices.
 428 // See the documentation of Experiment for details on the fields.
 429 //
 430 // Command-line switches must have entries in enum "LoginCustomFlags" in
 431 // histograms.xml. See note in histograms.xml and don't forget to run
 432 // AboutFlagsHistogramTest unit test to calculate and verify checksum.
 433 //
 434 // When adding a new choice, add it to the end of the list.
 435 const Experiment kExperiments[] = {
 436   {
 437     "ignore-gpu-blacklist",
 438     IDS_FLAGS_IGNORE_GPU_BLACKLIST_NAME,
 439     IDS_FLAGS_IGNORE_GPU_BLACKLIST_DESCRIPTION,
 440     kOsAll,
 441     SINGLE_VALUE_TYPE(switches::kIgnoreGpuBlacklist)
 442   },
 443 #if defined(OS_WIN)
 444   {
 445     "disable-direct-write",
 446     IDS_FLAGS_DISABLE_DIRECT_WRITE_NAME,
 447     IDS_FLAGS_DISABLE_DIRECT_WRITE_DESCRIPTION,
 448     kOsWin,
 449     SINGLE_VALUE_TYPE(switches::kDisableDirectWrite)
 450   },
 451   {
 452     "enable-win32k-renderer-lockdown",
 453     IDS_FLAGS_ENABLE_WIN32K_RENDERER_LOCKDOWN_NAME,
 454     IDS_FLAGS_ENABLE_WIN32K_RENDERER_LOCKDOWN_DESCRIPTION,
 455     kOsWin,
 456     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableWin32kRendererLockDown,
 457                               switches::kDisableWin32kRendererLockDown)
 458   },
 459 #endif
 460   {
 461     "enable-experimental-canvas-features",
 462     IDS_FLAGS_ENABLE_EXPERIMENTAL_CANVAS_FEATURES_NAME,
 463     IDS_FLAGS_ENABLE_EXPERIMENTAL_CANVAS_FEATURES_DESCRIPTION,
 464     kOsAll,
 465     SINGLE_VALUE_TYPE(switches::kEnableExperimentalCanvasFeatures)
 466   },
 467   {
 468     "disable-accelerated-2d-canvas",
 469     IDS_FLAGS_DISABLE_ACCELERATED_2D_CANVAS_NAME,
 470     IDS_FLAGS_DISABLE_ACCELERATED_2D_CANVAS_DESCRIPTION,
 471     kOsAll,
 472     SINGLE_VALUE_TYPE(switches::kDisableAccelerated2dCanvas)
 473   },
 474   {
 475     "enable-display-list-2d-canvas",
 476     IDS_FLAGS_ENABLE_DISPLAY_LIST_2D_CANVAS_NAME,
 477     IDS_FLAGS_ENABLE_DISPLAY_LIST_2D_CANVAS_DESCRIPTION,
 478     kOsAll,
 479     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableDisplayList2dCanvas,
 480                               switches::kDisableDisplayList2dCanvas)
 481   },
 482   {
 483     "composited-layer-borders",
 484     IDS_FLAGS_COMPOSITED_LAYER_BORDERS,
 485     IDS_FLAGS_COMPOSITED_LAYER_BORDERS_DESCRIPTION,
 486     kOsAll,
 487     SINGLE_VALUE_TYPE(cc::switches::kShowCompositedLayerBorders)
 488   },
 489   {
 490     "show-fps-counter",
 491     IDS_FLAGS_SHOW_FPS_COUNTER,
 492     IDS_FLAGS_SHOW_FPS_COUNTER_DESCRIPTION,
 493     kOsAll,
 494     SINGLE_VALUE_TYPE(cc::switches::kShowFPSCounter)
 495   },
 496   {
 497     "disable-webgl",
 498     IDS_FLAGS_DISABLE_WEBGL_NAME,
 499     IDS_FLAGS_DISABLE_WEBGL_DESCRIPTION,
 500     kOsAll,
 501     SINGLE_VALUE_TYPE(switches::kDisableExperimentalWebGL)
 502   },
 503   {
 504     "disable-webrtc",
 505     IDS_FLAGS_DISABLE_WEBRTC_NAME,
 506     IDS_FLAGS_DISABLE_WEBRTC_DESCRIPTION,
 507     kOsAndroid,
 508 #if defined(OS_ANDROID)
 509     SINGLE_VALUE_TYPE(switches::kDisableWebRTC)
 510 #else
 511     SINGLE_VALUE_TYPE("")
 512 #endif
 513   },
 514 #if defined(ENABLE_WEBRTC)
 515   {
 516     "disable-webrtc-hw-decoding",
 517     IDS_FLAGS_DISABLE_WEBRTC_HW_DECODING_NAME,
 518     IDS_FLAGS_DISABLE_WEBRTC_HW_DECODING_DESCRIPTION,
 519     kOsAndroid | kOsCrOS,
 520     SINGLE_VALUE_TYPE(switches::kDisableWebRtcHWDecoding)
 521   },
 522   {
 523     "disable-webrtc-hw-encoding",
 524     IDS_FLAGS_DISABLE_WEBRTC_HW_ENCODING_NAME,
 525     IDS_FLAGS_DISABLE_WEBRTC_HW_ENCODING_DESCRIPTION,
 526     kOsAndroid | kOsCrOS,
 527     SINGLE_VALUE_TYPE(switches::kDisableWebRtcHWEncoding)
 528   },
 529 #endif
 530 #if defined(OS_ANDROID)
 531   {
 532     "disable-webaudio",
 533     IDS_FLAGS_DISABLE_WEBAUDIO_NAME,
 534     IDS_FLAGS_DISABLE_WEBAUDIO_DESCRIPTION,
 535     kOsAndroid,
 536     SINGLE_VALUE_TYPE(switches::kDisableWebAudio)
 537   },
 538 #endif
 539   // Native client is compiled out when DISABLE_NACL is defined.
 540 #if !defined(DISABLE_NACL)
 541   {
 542     "enable-nacl",  // FLAGS:RECORD_UMA
 543     IDS_FLAGS_ENABLE_NACL_NAME,
 544     IDS_FLAGS_ENABLE_NACL_DESCRIPTION,
 545     kOsAll,
 546     SINGLE_VALUE_TYPE(switches::kEnableNaCl)
 547   },
 548   {
 549     "enable-nacl-debug",  // FLAGS:RECORD_UMA
 550     IDS_FLAGS_ENABLE_NACL_DEBUG_NAME,
 551     IDS_FLAGS_ENABLE_NACL_DEBUG_DESCRIPTION,
 552     kOsDesktop,
 553     SINGLE_VALUE_TYPE(switches::kEnableNaClDebug)
 554   },
 555   {
 556     "nacl-debug-mask",  // FLAGS:RECORD_UMA
 557     IDS_FLAGS_NACL_DEBUG_MASK_NAME,
 558     IDS_FLAGS_NACL_DEBUG_MASK_DESCRIPTION,
 559     kOsDesktop,
 560     MULTI_VALUE_TYPE(kNaClDebugMaskChoices)
 561   },
 562 #endif
 563 #if defined(ENABLE_EXTENSIONS)
 564   {
 565     "extension-apis",  // FLAGS:RECORD_UMA
 566     IDS_FLAGS_EXPERIMENTAL_EXTENSION_APIS_NAME,
 567     IDS_FLAGS_EXPERIMENTAL_EXTENSION_APIS_DESCRIPTION,
 568     kOsDesktop,
 569     SINGLE_VALUE_TYPE(extensions::switches::kEnableExperimentalExtensionApis)
 570   },
 571   {
 572     "extensions-on-chrome-urls",
 573     IDS_FLAGS_EXTENSIONS_ON_CHROME_URLS_NAME,
 574     IDS_FLAGS_EXTENSIONS_ON_CHROME_URLS_DESCRIPTION,
 575     kOsAll,
 576     SINGLE_VALUE_TYPE(extensions::switches::kExtensionsOnChromeURLs)
 577   },
 578 #endif
 579   {
 580     "enable-fast-unload",
 581     IDS_FLAGS_ENABLE_FAST_UNLOAD_NAME,
 582     IDS_FLAGS_ENABLE_FAST_UNLOAD_DESCRIPTION,
 583     kOsAll,
 584     SINGLE_VALUE_TYPE(switches::kEnableFastUnload)
 585   },
 586 #if defined(ENABLE_EXTENSIONS)
 587   {
 588     "enable-app-window-controls",
 589     IDS_FLAGS_ENABLE_APP_WINDOW_CONTROLS_NAME,
 590     IDS_FLAGS_ENABLE_APP_WINDOW_CONTROLS_DESCRIPTION,
 591     kOsDesktop,
 592     SINGLE_VALUE_TYPE(extensions::switches::kEnableAppWindowControls)
 593   },
 594 #endif
 595   {
 596     "disable-hyperlink-auditing",
 597     IDS_FLAGS_DISABLE_HYPERLINK_AUDITING_NAME,
 598     IDS_FLAGS_DISABLE_HYPERLINK_AUDITING_DESCRIPTION,
 599     kOsAll,
 600     SINGLE_VALUE_TYPE(switches::kNoPings)
 601   },
 602 #if defined(OS_ANDROID)
 603   {
 604     "contextual-search",
 605     IDS_FLAGS_ENABLE_CONTEXTUAL_SEARCH,
 606     IDS_FLAGS_ENABLE_CONTEXTUAL_SEARCH_DESCRIPTION,
 607     kOsAndroid,
 608     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableContextualSearch,
 609                               switches::kDisableContextualSearch)
 610   },
 611 #endif
 612   {
 613     "show-autofill-type-predictions",
 614     IDS_FLAGS_SHOW_AUTOFILL_TYPE_PREDICTIONS_NAME,
 615     IDS_FLAGS_SHOW_AUTOFILL_TYPE_PREDICTIONS_DESCRIPTION,
 616     kOsAll,
 617     SINGLE_VALUE_TYPE(autofill::switches::kShowAutofillTypePredictions)
 618   },
 619   {
 620     "enable-smooth-scrolling",  // FLAGS:RECORD_UMA
 621     IDS_FLAGS_ENABLE_SMOOTH_SCROLLING_NAME,
 622     IDS_FLAGS_ENABLE_SMOOTH_SCROLLING_DESCRIPTION,
 623     // Can't expose the switch unless the code is compiled in.
 624     // On by default for the Mac (different implementation in WebKit).
 625     kOsLinux,
 626     SINGLE_VALUE_TYPE(switches::kEnableSmoothScrolling)
 627   },
 628 #if defined(USE_AURA) || defined(OS_LINUX)
 629   {
 630     "overlay-scrollbars",
 631     IDS_FLAGS_ENABLE_OVERLAY_SCROLLBARS_NAME,
 632     IDS_FLAGS_ENABLE_OVERLAY_SCROLLBARS_DESCRIPTION,
 633     // Uses the system preference on Mac (a different implementation).
 634     // On Android, this is always enabled.
 635     kOsLinux | kOsCrOS | kOsWin,
 636     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableOverlayScrollbar,
 637                               switches::kDisableOverlayScrollbar)
 638   },
 639 #endif
 640   {
 641     "enable-panels",
 642     IDS_FLAGS_ENABLE_PANELS_NAME,
 643     IDS_FLAGS_ENABLE_PANELS_DESCRIPTION,
 644     kOsDesktop,
 645     SINGLE_VALUE_TYPE(switches::kEnablePanels)
 646   },
 647   {
 648     // See http://crbug.com/120416 for how to remove this flag.
 649     "save-page-as-mhtml",  // FLAGS:RECORD_UMA
 650     IDS_FLAGS_SAVE_PAGE_AS_MHTML_NAME,
 651     IDS_FLAGS_SAVE_PAGE_AS_MHTML_DESCRIPTION,
 652     kOsMac | kOsWin | kOsLinux,
 653     SINGLE_VALUE_TYPE(switches::kSavePageAsMHTML)
 654   },
 655   {
 656     "enable-quic",
 657     IDS_FLAGS_ENABLE_QUIC_NAME,
 658     IDS_FLAGS_ENABLE_QUIC_DESCRIPTION,
 659     kOsAll,
 660     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableQuic,
 661                               switches::kDisableQuic)
 662   },
 663   {
 664     "enable-spdy4",
 665     IDS_FLAGS_ENABLE_SPDY4_NAME,
 666     IDS_FLAGS_ENABLE_SPDY4_DESCRIPTION,
 667     kOsAll,
 668     SINGLE_VALUE_TYPE(switches::kEnableSpdy4)
 669   },
 670   {
 671     "enable-async-dns",
 672     IDS_FLAGS_ENABLE_ASYNC_DNS_NAME,
 673     IDS_FLAGS_ENABLE_ASYNC_DNS_DESCRIPTION,
 674     kOsWin | kOsMac | kOsLinux | kOsCrOS,
 675     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableAsyncDns,
 676                               switches::kDisableAsyncDns)
 677   },
 678   {
 679     "disable-media-source",
 680     IDS_FLAGS_DISABLE_MEDIA_SOURCE_NAME,
 681     IDS_FLAGS_DISABLE_MEDIA_SOURCE_DESCRIPTION,
 682     kOsAll,
 683     SINGLE_VALUE_TYPE(switches::kDisableMediaSource)
 684   },
 685   {
 686     "enable-encrypted-media",
 687     IDS_FLAGS_ENABLE_ENCRYPTED_MEDIA_NAME,
 688     IDS_FLAGS_ENABLE_ENCRYPTED_MEDIA_DESCRIPTION,
 689     kOsAll,
 690     SINGLE_VALUE_TYPE(switches::kEnableEncryptedMedia)
 691   },
 692   {
 693     "disable-prefixed-encrypted-media",
 694     IDS_FLAGS_DISABLE_PREFIXED_ENCRYPTED_MEDIA_NAME,
 695     IDS_FLAGS_DISABLE_PREFIXED_ENCRYPTED_MEDIA_DESCRIPTION,
 696     kOsAll,
 697     SINGLE_VALUE_TYPE(switches::kDisablePrefixedEncryptedMedia)
 698   },
 699 #if defined(OS_ANDROID)
 700   {
 701     "disable-infobar-for-protected-media-identifier",
 702     IDS_FLAGS_DISABLE_INFOBAR_FOR_PROTECTED_MEDIA_IDENTIFIER_NAME,
 703     IDS_FLAGS_DISABLE_INFOBAR_FOR_PROTECTED_MEDIA_IDENTIFIER_DESCRIPTION,
 704     kOsAndroid,
 705     SINGLE_VALUE_TYPE(switches::kDisableInfobarForProtectedMediaIdentifier)
 706   },
 707   {
 708     "mediadrm-enable-non-compositing",
 709     IDS_FLAGS_MEDIADRM_ENABLE_NON_COMPOSITING_NAME,
 710     IDS_FLAGS_MEDIADRM_ENABLE_NON_COMPOSITING_DESCRIPTION,
 711     kOsAndroid,
 712     SINGLE_VALUE_TYPE(switches::kMediaDrmEnableNonCompositing)
 713   },
 714 #endif  // defined(OS_ANDROID)
 715   {
 716     "disable-javascript-harmony-shipping",
 717     IDS_FLAGS_DISABLE_JAVASCRIPT_HARMONY_SHIPPING_NAME,
 718     IDS_FLAGS_DISABLE_JAVASCRIPT_HARMONY_SHIPPING_DESCRIPTION,
 719     kOsAll,
 720     SINGLE_VALUE_TYPE(switches::kDisableJavaScriptHarmonyShipping)
 721   },
 722   {
 723     "enable-javascript-harmony",
 724     IDS_FLAGS_ENABLE_JAVASCRIPT_HARMONY_NAME,
 725     IDS_FLAGS_ENABLE_JAVASCRIPT_HARMONY_DESCRIPTION,
 726     kOsAll,
 727     SINGLE_VALUE_TYPE(switches::kJavaScriptHarmony)
 728   },
 729   {
 730     "disable-software-rasterizer",
 731     IDS_FLAGS_DISABLE_SOFTWARE_RASTERIZER_NAME,
 732     IDS_FLAGS_DISABLE_SOFTWARE_RASTERIZER_DESCRIPTION,
 733 #if defined(ENABLE_SWIFTSHADER)
 734     kOsAll,
 735 #else
 736     0,
 737 #endif
 738     SINGLE_VALUE_TYPE(switches::kDisableSoftwareRasterizer)
 739   },
 740   {
 741     "enable-gpu-rasterization",
 742     IDS_FLAGS_ENABLE_GPU_RASTERIZATION_NAME,
 743     IDS_FLAGS_ENABLE_GPU_RASTERIZATION_DESCRIPTION,
 744     kOsAll,
 745     MULTI_VALUE_TYPE(kEnableGpuRasterizationChoices)
 746   },
 747   {
 748     "enable-experimental-web-platform-features",
 749     IDS_FLAGS_EXPERIMENTAL_WEB_PLATFORM_FEATURES_NAME,
 750     IDS_FLAGS_EXPERIMENTAL_WEB_PLATFORM_FEATURES_DESCRIPTION,
 751     kOsAll,
 752     SINGLE_VALUE_TYPE(switches::kEnableExperimentalWebPlatformFeatures)
 753   },
 754   {
 755     "disable-ntp-other-sessions-menu",
 756     IDS_FLAGS_NTP_OTHER_SESSIONS_MENU_NAME,
 757     IDS_FLAGS_NTP_OTHER_SESSIONS_MENU_DESCRIPTION,
 758     kOsDesktop,
 759     SINGLE_VALUE_TYPE(switches::kDisableNTPOtherSessionsMenu)
 760   },
 761   {
 762     "enable-devtools-experiments",
 763     IDS_FLAGS_ENABLE_DEVTOOLS_EXPERIMENTS_NAME,
 764     IDS_FLAGS_ENABLE_DEVTOOLS_EXPERIMENTS_DESCRIPTION,
 765     kOsDesktop,
 766     SINGLE_VALUE_TYPE(switches::kEnableDevToolsExperiments)
 767   },
 768   {
 769     "silent-debugger-extension-api",
 770     IDS_FLAGS_SILENT_DEBUGGER_EXTENSION_API_NAME,
 771     IDS_FLAGS_SILENT_DEBUGGER_EXTENSION_API_DESCRIPTION,
 772     kOsDesktop,
 773     SINGLE_VALUE_TYPE(switches::kSilentDebuggerExtensionAPI)
 774   },
 775 #if defined(ENABLE_SPELLCHECK)
 776   {
 777     "spellcheck-autocorrect",
 778     IDS_FLAGS_SPELLCHECK_AUTOCORRECT,
 779     IDS_FLAGS_SPELLCHECK_AUTOCORRECT_DESCRIPTION,
 780     kOsWin | kOsLinux | kOsCrOS,
 781     SINGLE_VALUE_TYPE(switches::kEnableSpellingAutoCorrect)
 782   },
 783 #endif
 784   {
 785     "enable-scroll-prediction",
 786     IDS_FLAGS_ENABLE_SCROLL_PREDICTION_NAME,
 787     IDS_FLAGS_ENABLE_SCROLL_PREDICTION_DESCRIPTION,
 788     kOsDesktop,
 789     SINGLE_VALUE_TYPE(switches::kEnableScrollPrediction)
 790   },
 791   {
 792     "touch-events",
 793     IDS_TOUCH_EVENTS_NAME,
 794     IDS_TOUCH_EVENTS_DESCRIPTION,
 795     kOsDesktop,
 796     MULTI_VALUE_TYPE(kTouchEventsChoices)
 797   },
 798   {
 799     "disable-touch-adjustment",
 800     IDS_DISABLE_TOUCH_ADJUSTMENT_NAME,
 801     IDS_DISABLE_TOUCH_ADJUSTMENT_DESCRIPTION,
 802     kOsWin | kOsLinux | kOsCrOS | kOsAndroid,
 803     SINGLE_VALUE_TYPE(switches::kDisableTouchAdjustment)
 804   },
 805 #if defined(OS_CHROMEOS)
 806   {
 807     "network-portal-notification",
 808     IDS_FLAGS_NETWORK_PORTAL_NOTIFICATION_NAME,
 809     IDS_FLAGS_NETWORK_PORTAL_NOTIFICATION_DESCRIPTION,
 810     kOsCrOS,
 811     ENABLE_DISABLE_VALUE_TYPE(
 812         chromeos::switches::kEnableNetworkPortalNotification,
 813         chromeos::switches::kDisableNetworkPortalNotification)
 814   },
 815 #endif
 816   {
 817     "enable-download-resumption",
 818     IDS_FLAGS_ENABLE_DOWNLOAD_RESUMPTION_NAME,
 819     IDS_FLAGS_ENABLE_DOWNLOAD_RESUMPTION_DESCRIPTION,
 820     kOsDesktop,
 821     SINGLE_VALUE_TYPE(switches::kEnableDownloadResumption)
 822   },
 823 #if defined(ENABLE_PLUGINS)
 824   {
 825     "allow-nacl-socket-api",
 826     IDS_FLAGS_ALLOW_NACL_SOCKET_API_NAME,
 827     IDS_FLAGS_ALLOW_NACL_SOCKET_API_DESCRIPTION,
 828     kOsDesktop,
 829     SINGLE_VALUE_TYPE_AND_VALUE(switches::kAllowNaClSocketAPI, "*")
 830   },
 831 #endif
 832 #if defined(OS_CHROMEOS)
 833   {
 834     "allow-touchpad-three-finger-click",
 835     IDS_FLAGS_ALLOW_TOUCHPAD_THREE_FINGER_CLICK_NAME,
 836     IDS_FLAGS_ALLOW_TOUCHPAD_THREE_FINGER_CLICK_DESCRIPTION,
 837     kOsCrOS,
 838     SINGLE_VALUE_TYPE(chromeos::switches::kEnableTouchpadThreeFingerClick)
 839   },
 840   {
 841     "disable-easy-unlock",
 842     IDS_FLAGS_DISABLE_EASY_UNLOCK_NAME,
 843     IDS_FLAGS_DISABLE_EASY_UNLOCK_DESCRIPTION,
 844     kOsCrOS,
 845     SINGLE_VALUE_TYPE(proximity_auth::switches::kDisableEasyUnlock)
 846   },
 847   {
 848     "enable-easy-unlock-proximity-detection",
 849     IDS_FLAGS_ENABLE_EASY_UNLOCK_PROXIMITY_DETECTION_NAME,
 850     IDS_FLAGS_ENABLE_EASY_UNLOCK_PROXIMITY_DETECTION_DESCRIPTION,
 851     kOsCrOS,
 852     SINGLE_VALUE_TYPE(proximity_auth::switches::kEnableProximityDetection)
 853   },
 854 #endif
 855 #if defined(USE_ASH)
 856   {
 857     "disable-minimize-on-second-launcher-item-click",
 858     IDS_FLAGS_DISABLE_MINIMIZE_ON_SECOND_LAUNCHER_ITEM_CLICK_NAME,
 859     IDS_FLAGS_DISABLE_MINIMIZE_ON_SECOND_LAUNCHER_ITEM_CLICK_DESCRIPTION,
 860     kOsAll,
 861     SINGLE_VALUE_TYPE(switches::kDisableMinimizeOnSecondLauncherItemClick)
 862   },
 863   {
 864     "show-touch-hud",
 865     IDS_FLAGS_SHOW_TOUCH_HUD_NAME,
 866     IDS_FLAGS_SHOW_TOUCH_HUD_DESCRIPTION,
 867     kOsAll,
 868     SINGLE_VALUE_TYPE(ash::switches::kAshTouchHud)
 869   },
 870   {
 871     "enable-pinch",
 872     IDS_FLAGS_ENABLE_PINCH_SCALE_NAME,
 873     IDS_FLAGS_ENABLE_PINCH_SCALE_DESCRIPTION,
 874     kOsLinux | kOsWin | kOsCrOS,
 875     ENABLE_DISABLE_VALUE_TYPE(switches::kEnablePinch, switches::kDisablePinch),
 876   },
 877 #endif  // defined(USE_ASH)
 878   {
 879     "enable-pinch-virtual-viewport",
 880     IDS_FLAGS_ENABLE_PINCH_VIRTUAL_VIEWPORT_NAME,
 881     IDS_FLAGS_ENABLE_PINCH_VIRTUAL_VIEWPORT_DESCRIPTION,
 882     kOsLinux | kOsWin | kOsCrOS | kOsAndroid,
 883     ENABLE_DISABLE_VALUE_TYPE(
 884         cc::switches::kEnablePinchVirtualViewport,
 885         cc::switches::kDisablePinchVirtualViewport),
 886   },
 887   {
 888     "enable-viewport-meta",
 889     IDS_FLAGS_ENABLE_VIEWPORT_META_NAME,
 890     IDS_FLAGS_ENABLE_VIEWPORT_META_DESCRIPTION,
 891     kOsLinux | kOsWin | kOsCrOS | kOsMac,
 892     SINGLE_VALUE_TYPE(switches::kEnableViewportMeta),
 893   },
 894 #if defined(OS_CHROMEOS)
 895   {
 896     "disable-boot-animation",
 897     IDS_FLAGS_DISABLE_BOOT_ANIMATION,
 898     IDS_FLAGS_DISABLE_BOOT_ANIMATION_DESCRIPTION,
 899     kOsCrOSOwnerOnly,
 900     SINGLE_VALUE_TYPE(chromeos::switches::kDisableBootAnimation),
 901   },
 902   {
 903     "enable-video-player-chromecast-support",
 904     IDS_FLAGS_ENABLE_VIDEO_PLAYER_CHROMECAST_SUPPORT_NAME,
 905     IDS_FLAGS_ENABLE_VIDEO_PLAYER_CHROMECAST_SUPPORT_DESCRIPTION,
 906     kOsCrOS,
 907     SINGLE_VALUE_TYPE(chromeos::switches::kEnableVideoPlayerChromecastSupport)
 908   },
 909   {
 910     "disable-office-editing-component-app",
 911     IDS_FLAGS_DISABLE_OFFICE_EDITING_COMPONENT_APP_NAME,
 912     IDS_FLAGS_DISABLE_OFFICE_EDITING_COMPONENT_APP_DESCRIPTION,
 913     kOsCrOS,
 914     SINGLE_VALUE_TYPE(chromeos::switches::kDisableOfficeEditingComponentApp),
 915   },
 916   {
 917     "disable-display-color-calibration",
 918     IDS_FLAGS_DISABLE_DISPLAY_COLOR_CALIBRATION_NAME,
 919     IDS_FLAGS_DISABLE_DISPLAY_COLOR_CALIBRATION_DESCRIPTION,
 920     kOsCrOS,
 921     SINGLE_VALUE_TYPE(ui::switches::kDisableDisplayColorCalibration),
 922   },
 923 #endif  // defined(OS_CHROMEOS)
 924   { "disable-accelerated-video-decode",
 925     IDS_FLAGS_DISABLE_ACCELERATED_VIDEO_DECODE_NAME,
 926     IDS_FLAGS_DISABLE_ACCELERATED_VIDEO_DECODE_DESCRIPTION,
 927     kOsWin | kOsCrOS,
 928     SINGLE_VALUE_TYPE(switches::kDisableAcceleratedVideoDecode),
 929   },
 930 #if defined(USE_ASH)
 931   {
 932     "ash-debug-shortcuts",
 933     IDS_FLAGS_DEBUG_SHORTCUTS_NAME,
 934     IDS_FLAGS_DEBUG_SHORTCUTS_DESCRIPTION,
 935     kOsAll,
 936     SINGLE_VALUE_TYPE(ash::switches::kAshDebugShortcuts),
 937   },
 938   { "ash-enable-touch-view-testing",
 939     IDS_FLAGS_ASH_ENABLE_TOUCH_VIEW_TESTING_NAME,
 940     IDS_FLAGS_ASH_ENABLE_TOUCH_VIEW_TESTING_DESCRIPTION,
 941     kOsCrOS,
 942     SINGLE_VALUE_TYPE(ash::switches::kAshEnableTouchViewTesting),
 943   },
 944   {
 945     "disable-touch-feedback",
 946     IDS_FLAGS_DISABLE_TOUCH_FEEDBACK_NAME,
 947     IDS_FLAGS_DISABLE_TOUCH_FEEDBACK_DESCRIPTION,
 948     kOsCrOS,
 949     SINGLE_VALUE_TYPE(switches::kDisableTouchFeedback),
 950   },
 951   { "ash-disable-text-filtering-in-overview-mode",
 952     IDS_FLAGS_ASH_DISABLE_TEXT_FILTERING_IN_OVERVIEW_MODE_NAME,
 953     IDS_FLAGS_ASH_DISABLE_TEXT_FILTERING_IN_OVERVIEW_MODE_DESCRIPTION,
 954     kOsCrOS,
 955     SINGLE_VALUE_TYPE(ash::switches::kAshDisableTextFilteringInOverviewMode),
 956   },
 957   { "ash-enable-mirrored-screen",
 958     IDS_FLAGS_ASH_ENABLE_MIRRORED_SCREEN_NAME,
 959     IDS_FLAGS_ASH_ENABLE_MIRRORED_SCREEN_DESCRIPTION,
 960     kOsCrOS,
 961     SINGLE_VALUE_TYPE(ash::switches::kAshEnableMirroredScreen),
 962   },
 963 #endif  // defined(USE_ASH)
 964 #if defined(OS_CHROMEOS)
 965   {
 966     "enable-carrier-switching",
 967     IDS_FLAGS_ENABLE_CARRIER_SWITCHING,
 968     IDS_FLAGS_ENABLE_CARRIER_SWITCHING_DESCRIPTION,
 969     kOsCrOS,
 970     SINGLE_VALUE_TYPE(chromeos::switches::kEnableCarrierSwitching)
 971   },
 972   {
 973     "enable-cloud-backup",
 974     IDS_FLAGS_ENABLE_CLOUD_BACKUP,
 975     IDS_FLAGS_ENABLE_CLOUD_BACKUP_DESCRIPTION,
 976     kOsCrOS,
 977     SINGLE_VALUE_TYPE(chromeos::switches::kEnableCloudBackup)
 978   },
 979   {
 980     "enable-request-tablet-site",
 981     IDS_FLAGS_ENABLE_REQUEST_TABLET_SITE_NAME,
 982     IDS_FLAGS_ENABLE_REQUEST_TABLET_SITE_DESCRIPTION,
 983     kOsCrOS,
 984     SINGLE_VALUE_TYPE(chromeos::switches::kEnableRequestTabletSite)
 985   },
 986 #endif
 987   {
 988     "debug-packed-apps",
 989     IDS_FLAGS_DEBUG_PACKED_APP_NAME,
 990     IDS_FLAGS_DEBUG_PACKED_APP_DESCRIPTION,
 991     kOsDesktop,
 992     SINGLE_VALUE_TYPE(switches::kDebugPackedApps)
 993   },
 994   {
 995     "enable-password-generation",
 996     IDS_FLAGS_ENABLE_PASSWORD_GENERATION_NAME,
 997     IDS_FLAGS_ENABLE_PASSWORD_GENERATION_DESCRIPTION,
 998     kOsWin | kOsLinux | kOsCrOS | kOsMac | kOsAndroid,
 999     ENABLE_DISABLE_VALUE_TYPE(autofill::switches::kEnablePasswordGeneration,
1000                               autofill::switches::kDisablePasswordGeneration)
1001   },
1002   {
1003     "enable-automatic-password-saving",
1004     IDS_FLAGS_ENABLE_AUTOMATIC_PASSWORD_SAVING_NAME,
1005     IDS_FLAGS_ENABLE_AUTOMATIC_PASSWORD_SAVING_DESCRIPTION,
1006     kOsDesktop,
1007     SINGLE_VALUE_TYPE(
1008         password_manager::switches::kEnableAutomaticPasswordSaving)
1009   },
1010   {
1011     "password-manager-reauthentication",
1012     IDS_FLAGS_PASSWORD_MANAGER_REAUTHENTICATION_NAME,
1013     IDS_FLAGS_PASSWORD_MANAGER_REAUTHENTICATION_DESCRIPTION,
1014     kOsMac | kOsWin,
1015     SINGLE_VALUE_TYPE(switches::kDisablePasswordManagerReauthentication)
1016   },
1017   {
1018     "enable-password-link",
1019     IDS_FLAGS_PASSWORD_MANAGER_LINK_NAME,
1020     IDS_FLAGS_PASSWORD_MANAGER_LINK_DESCRIPTION,
1021     kOsAndroid | kOsDesktop,
1022     ENABLE_DISABLE_VALUE_TYPE(
1023         password_manager::switches::kEnablePasswordLink,
1024         password_manager::switches::kDisablePasswordLink)
1025   },
1026   {
1027     "enable-deferred-image-decoding",
1028     IDS_FLAGS_ENABLE_DEFERRED_IMAGE_DECODING_NAME,
1029     IDS_FLAGS_ENABLE_DEFERRED_IMAGE_DECODING_DESCRIPTION,
1030     kOsMac | kOsLinux | kOsCrOS,
1031     SINGLE_VALUE_TYPE(switches::kEnableDeferredImageDecoding)
1032   },
1033   {
1034     "wallet-service-use-sandbox",
1035     IDS_FLAGS_WALLET_SERVICE_USE_SANDBOX_NAME,
1036     IDS_FLAGS_WALLET_SERVICE_USE_SANDBOX_DESCRIPTION,
1037     kOsAndroid | kOsDesktop,
1038     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(
1039         autofill::switches::kWalletServiceUseSandbox, "1",
1040         autofill::switches::kWalletServiceUseSandbox, "0")
1041   },
1042 #if defined(USE_AURA)
1043   {
1044     "overscroll-history-navigation",
1045     IDS_FLAGS_OVERSCROLL_HISTORY_NAVIGATION_NAME,
1046     IDS_FLAGS_OVERSCROLL_HISTORY_NAVIGATION_DESCRIPTION,
1047     kOsAll,
1048     MULTI_VALUE_TYPE(kOverscrollHistoryNavigationChoices)
1049   },
1050 #endif
1051   {
1052     "scroll-end-effect",
1053     IDS_FLAGS_SCROLL_END_EFFECT_NAME,
1054     IDS_FLAGS_SCROLL_END_EFFECT_DESCRIPTION,
1055     kOsCrOS,
1056     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(
1057         switches::kScrollEndEffect, "1",
1058         switches::kScrollEndEffect, "0")
1059   },
1060   {
1061     "enable-renderer-mojo-channel",
1062     IDS_FLAGS_ENABLE_RENDERER_MOJO_CHANNEL_NAME,
1063     IDS_FLAGS_ENABLE_RENDERER_MOJO_CHANNEL_DESCRIPTION,
1064     kOsAll,
1065     SINGLE_VALUE_TYPE(switches::kEnableRendererMojoChannel)
1066   },
1067   {
1068     "enable-touch-drag-drop",
1069     IDS_FLAGS_ENABLE_TOUCH_DRAG_DROP_NAME,
1070     IDS_FLAGS_ENABLE_TOUCH_DRAG_DROP_DESCRIPTION,
1071     kOsWin | kOsCrOS,
1072     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableTouchDragDrop,
1073                               switches::kDisableTouchDragDrop)
1074   },
1075   {
1076     "enable-touch-editing",
1077     IDS_FLAGS_ENABLE_TOUCH_EDITING_NAME,
1078     IDS_FLAGS_ENABLE_TOUCH_EDITING_DESCRIPTION,
1079     kOsCrOS | kOsWin | kOsLinux,
1080     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableTouchEditing,
1081                               switches::kDisableTouchEditing)
1082   },
1083   {
1084     "enable-stale-while-revalidate",
1085     IDS_FLAGS_ENABLE_STALE_WHILE_REVALIDATE_NAME,
1086     IDS_FLAGS_ENABLE_STALE_WHILE_REVALIDATE_DESCRIPTION,
1087     kOsAll,
1088     SINGLE_VALUE_TYPE(switches::kEnableStaleWhileRevalidate)
1089   },
1090   {
1091     "enable-suggestions-service",
1092     IDS_FLAGS_ENABLE_SUGGESTIONS_SERVICE_NAME,
1093     IDS_FLAGS_ENABLE_SUGGESTIONS_SERVICE_DESCRIPTION,
1094     kOsAndroid | kOsCrOS,
1095     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSuggestionsService,
1096                               switches::kDisableSuggestionsService)
1097   },
1098   {
1099     "enable-supervised-user-blacklist",
1100     IDS_FLAGS_ENABLE_SUPERVISED_USER_BLACKLIST_NAME,
1101     IDS_FLAGS_ENABLE_SUPERVISED_USER_BLACKLIST_DESCRIPTION,
1102     kOsAndroid | kOsMac | kOsWin | kOsLinux | kOsCrOS,
1103     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSupervisedUserBlacklist,
1104                               switches::kDisableSupervisedUserBlacklist)
1105   },
1106   {
1107     "enable-supervised-user-safesites",
1108     IDS_FLAGS_ENABLE_SUPERVISED_USER_SAFESITES_NAME,
1109     IDS_FLAGS_ENABLE_SUPERVISED_USER_SAFESITES_DESCRIPTION,
1110     kOsAndroid | kOsMac | kOsWin | kOsLinux | kOsCrOS,
1111     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSupervisedUserSafeSites,
1112                               switches::kDisableSupervisedUserSafeSites)
1113   },
1114 #if defined(ENABLE_APP_LIST)
1115   {
1116     "enable-sync-app-list",
1117     IDS_FLAGS_ENABLE_SYNC_APP_LIST_NAME,
1118     IDS_FLAGS_ENABLE_SYNC_APP_LIST_DESCRIPTION,
1119     kOsDesktop,
1120     ENABLE_DISABLE_VALUE_TYPE(app_list::switches::kEnableSyncAppList,
1121                               app_list::switches::kDisableSyncAppList)
1122   },
1123 #endif
1124 #if defined(OS_MACOSX)
1125   {
1126     "enable-avfoundation",
1127     IDS_FLAGS_ENABLE_AVFOUNDATION_NAME,
1128     IDS_FLAGS_ENABLE_AVFOUNDATION_DESCRIPTION,
1129     kOsMac,
1130     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableAVFoundation,
1131                               switches::kForceQTKit)
1132   },
1133 #endif
1134   {
1135     "impl-side-painting",
1136     IDS_FLAGS_IMPL_SIDE_PAINTING_NAME,
1137     IDS_FLAGS_IMPL_SIDE_PAINTING_DESCRIPTION,
1138     kOsAll,
1139     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableImplSidePainting,
1140                               switches::kDisableImplSidePainting)
1141   },
1142   {
1143     "lcd-text-aa",
1144     IDS_FLAGS_LCD_TEXT_NAME,
1145     IDS_FLAGS_LCD_TEXT_DESCRIPTION,
1146     kOsDesktop,
1147     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableLCDText,
1148                               switches::kDisableLCDText)
1149   },
1150 #if defined(OS_ANDROID) || defined(OS_MACOSX)
1151   {
1152     "delegated-renderer",
1153     IDS_FLAGS_DELEGATED_RENDERER_NAME,
1154     IDS_FLAGS_DELEGATED_RENDERER_DESCRIPTION,
1155     kOsAndroid,  // TODO(ccameron) Add mac support soon.
1156     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableDelegatedRenderer,
1157                               switches::kDisableDelegatedRenderer)
1158   },
1159 #endif
1160   {
1161     "max-tiles-for-interest-area",
1162     IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_NAME,
1163     IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_DESCRIPTION,
1164     kOsAll,
1165     MULTI_VALUE_TYPE(kMaxTilesForInterestAreaChoices)
1166   },
1167   {
1168     "enable-offline-auto-reload",
1169     IDS_FLAGS_ENABLE_OFFLINE_AUTO_RELOAD_NAME,
1170     IDS_FLAGS_ENABLE_OFFLINE_AUTO_RELOAD_DESCRIPTION,
1171     kOsAll,
1172     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableOfflineAutoReload,
1173                               switches::kDisableOfflineAutoReload)
1174   },
1175   {
1176     "enable-offline-auto-reload-visible-only",
1177     IDS_FLAGS_ENABLE_OFFLINE_AUTO_RELOAD_VISIBLE_ONLY_NAME,
1178     IDS_FLAGS_ENABLE_OFFLINE_AUTO_RELOAD_VISIBLE_ONLY_DESCRIPTION,
1179     kOsAll,
1180     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableOfflineAutoReloadVisibleOnly,
1181                               switches::kDisableOfflineAutoReloadVisibleOnly)
1182   },
1183   {
1184     "enable-offline-load-stale-cache",
1185     IDS_FLAGS_ENABLE_OFFLINE_LOAD_STALE_NAME,
1186     IDS_FLAGS_ENABLE_OFFLINE_LOAD_STALE_DESCRIPTION,
1187     kOsAll,
1188     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableOfflineLoadStaleCache,
1189                               switches::kDisableOfflineLoadStaleCache)
1190   },
1191   {
1192     "default-tile-width",
1193     IDS_FLAGS_DEFAULT_TILE_WIDTH_NAME,
1194     IDS_FLAGS_DEFAULT_TILE_WIDTH_DESCRIPTION,
1195     kOsAll,
1196     MULTI_VALUE_TYPE(kDefaultTileWidthChoices)
1197   },
1198   {
1199     "default-tile-height",
1200     IDS_FLAGS_DEFAULT_TILE_HEIGHT_NAME,
1201     IDS_FLAGS_DEFAULT_TILE_HEIGHT_DESCRIPTION,
1202     kOsAll,
1203     MULTI_VALUE_TYPE(kDefaultTileHeightChoices)
1204   },
1205 #if defined(OS_ANDROID)
1206   {
1207     "disable-gesture-requirement-for-media-playback",
1208     IDS_FLAGS_DISABLE_GESTURE_REQUIREMENT_FOR_MEDIA_PLAYBACK_NAME,
1209     IDS_FLAGS_DISABLE_GESTURE_REQUIREMENT_FOR_MEDIA_PLAYBACK_DESCRIPTION,
1210     kOsAndroid,
1211     SINGLE_VALUE_TYPE(switches::kDisableGestureRequirementForMediaPlayback)
1212   },
1213 #endif
1214 #if defined(ENABLE_EXTENSIONS)
1215   {
1216     "disable-extension-info-dialog",
1217     IDS_FLAGS_DISABLE_EXTENSION_INFO_DIALOG_NAME,
1218     IDS_FLAGS_DISABLE_EXTENSION_INFO_DIALOG_DESCRIPTION,
1219     kOsWin | kOsLinux | kOsCrOS,
1220     SINGLE_VALUE_TYPE(extensions::switches::kDisableExtensionInfoDialog)
1221   },
1222 #endif
1223 #if defined(OS_CHROMEOS)
1224   {
1225     "enable-virtual-keyboard",
1226     IDS_FLAGS_ENABLE_VIRTUAL_KEYBOARD_NAME,
1227     IDS_FLAGS_ENABLE_VIRTUAL_KEYBOARD_DESCRIPTION,
1228     kOsCrOS,
1229     SINGLE_VALUE_TYPE(keyboard::switches::kEnableVirtualKeyboard)
1230   },
1231   {
1232     "enable-virtual-keyboard-overscroll",
1233     IDS_FLAGS_ENABLE_VIRTUAL_KEYBOARD_OVERSCROLL_NAME,
1234     IDS_FLAGS_ENABLE_VIRTUAL_KEYBOARD_OVERSCROLL_DESCRIPTION,
1235     kOsCrOS,
1236     ENABLE_DISABLE_VALUE_TYPE(
1237         keyboard::switches::kEnableVirtualKeyboardOverscroll,
1238         keyboard::switches::kDisableVirtualKeyboardOverscroll)
1239   },
1240   {
1241     "enable-swipe-selection",
1242     IDS_FLAGS_ENABLE_SWIPE_SELECTION_NAME,
1243     IDS_FLAGS_ENABLE_SWIPE_SELECTION_DESCRIPTION,
1244     kOsCrOS,
1245     SINGLE_VALUE_TYPE(keyboard::switches::kEnableSwipeSelection)
1246   },
1247   {
1248     "enable-input-view",
1249     IDS_FLAGS_ENABLE_INPUT_VIEW_NAME,
1250     IDS_FLAGS_ENABLE_INPUT_VIEW_DESCRIPTION,
1251     kOsCrOS,
1252     ENABLE_DISABLE_VALUE_TYPE(keyboard::switches::kEnableInputView,
1253                               keyboard::switches::kDisableInputView)
1254   },
1255   {
1256     "enable-new-korean-ime",
1257     IDS_FLAGS_ENABLE_NEW_KOREAN_IME_NAME,
1258     IDS_FLAGS_ENABLE_NEW_KOREAN_IME_DESCRIPTION,
1259     kOsCrOS,
1260     SINGLE_VALUE_TYPE(chromeos::switches::kEnableNewKoreanIme)
1261   },
1262   {
1263     "enable-new-qp-input-view",
1264     IDS_FLAGS_ENABLE_NEW_QP_INPUT_VIEW_NAME,
1265     IDS_FLAGS_ENABLE_NEW_QP_INPUT_VIEW_DESCRIPTION,
1266     kOsCrOS,
1267     SINGLE_VALUE_TYPE(chromeos::switches::kEnableNewQPInputView)
1268   },
1269   {
1270     "enable-physical-keyboard-autocorrect",
1271     IDS_FLAGS_ENABLE_PHYSICAL_KEYBOARD_AUTOCORRECT_NAME,
1272     IDS_FLAGS_ENABLE_PHYSICAL_KEYBOARD_AUTOCORRECT_DESCRIPTION,
1273     kOsCrOS,
1274     SINGLE_VALUE_TYPE(chromeos::switches::kEnablePhysicalKeyboardAutocorrect)
1275   },
1276   {
1277     "enable-experimental-input-view-features",
1278     IDS_FLAGS_ENABLE_EXPERIMENTAL_INPUT_VIEW_FEATURES_NAME,
1279     IDS_FLAGS_ENABLE_EXPERIMENTAL_INPUT_VIEW_FEATURES_DESCRIPTION,
1280     kOsCrOS,
1281     SINGLE_VALUE_TYPE(keyboard::switches::kEnableExperimentalInputViewFeatures)
1282   },
1283   {
1284     "disable-smart-virtual-keyboard",
1285     IDS_FLAGS_DISABLE_SMART_VIRTUAL_KEYBOARD_NAME,
1286     IDS_FLAGS_DISABLE_SMART_VIRTUAL_KEYBOARD_DESCRIPTION,
1287     kOsCrOS,
1288     SINGLE_VALUE_TYPE(keyboard::switches::kDisableSmartVirtualKeyboard)
1289   },
1290 #endif
1291   {
1292     "enable-simple-cache-backend",
1293     IDS_FLAGS_ENABLE_SIMPLE_CACHE_BACKEND_NAME,
1294     IDS_FLAGS_ENABLE_SIMPLE_CACHE_BACKEND_DESCRIPTION,
1295     kOsWin | kOsMac | kOsLinux | kOsCrOS,
1296     MULTI_VALUE_TYPE(kSimpleCacheBackendChoices)
1297   },
1298   {
1299     "enable-tcp-fast-open",
1300     IDS_FLAGS_ENABLE_TCP_FAST_OPEN_NAME,
1301     IDS_FLAGS_ENABLE_TCP_FAST_OPEN_DESCRIPTION,
1302     kOsLinux | kOsCrOS | kOsAndroid,
1303     SINGLE_VALUE_TYPE(switches::kEnableTcpFastOpen)
1304   },
1305 #if defined(ENABLE_SERVICE_DISCOVERY)
1306   {
1307     "device-discovery-notifications",
1308     IDS_FLAGS_DEVICE_DISCOVERY_NOTIFICATIONS_NAME,
1309     IDS_FLAGS_DEVICE_DISCOVERY_NOTIFICATIONS_DESCRIPTION,
1310     kOsDesktop,
1311     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableDeviceDiscoveryNotifications,
1312                               switches::kDisableDeviceDiscoveryNotifications)
1313   },
1314   {
1315     "enable-cloud-devices",
1316     IDS_FLAGS_ENABLE_CLOUD_DEVICES_NAME,
1317     IDS_FLAGS_ENABLE_CLOUD_DEVICES_DESCRIPTION,
1318     kOsDesktop,
1319     SINGLE_VALUE_TYPE(switches::kEnableCloudDevices)
1320   },
1321   {
1322     "enable-print-preview-register-promos",
1323     IDS_FLAGS_ENABLE_PRINT_PREVIEW_REGISTER_PROMOS_NAME,
1324     IDS_FLAGS_ENABLE_PRINT_PREVIEW_REGISTER_PROMOS_DESCRIPTION,
1325     kOsDesktop,
1326     SINGLE_VALUE_TYPE(switches::kEnablePrintPreviewRegisterPromos)
1327   },
1328 #endif  // ENABLE_SERVICE_DISCOVERY
1329 #if defined(OS_WIN)
1330   {
1331     "enable-cloud-print-xps",
1332     IDS_FLAGS_ENABLE_CLOUD_PRINT_XPS_NAME,
1333     IDS_FLAGS_ENABLE_CLOUD_PRINT_XPS_DESCRIPTION,
1334     kOsWin,
1335     SINGLE_VALUE_TYPE(switches::kEnableCloudPrintXps)
1336   },
1337 #endif
1338 #if defined(USE_AURA)
1339   {
1340     "tab-capture-upscale-quality",
1341     IDS_FLAGS_TAB_CAPTURE_UPSCALE_QUALITY_NAME,
1342     IDS_FLAGS_TAB_CAPTURE_UPSCALE_QUALITY_DESCRIPTION,
1343     kOsAll,
1344     MULTI_VALUE_TYPE(kTabCaptureUpscaleQualityChoices)
1345   },
1346   {
1347     "tab-capture-downscale-quality",
1348     IDS_FLAGS_TAB_CAPTURE_DOWNSCALE_QUALITY_NAME,
1349     IDS_FLAGS_TAB_CAPTURE_DOWNSCALE_QUALITY_DESCRIPTION,
1350     kOsAll,
1351     MULTI_VALUE_TYPE(kTabCaptureDownscaleQualityChoices)
1352   },
1353 #endif
1354 #if defined(ENABLE_SPELLCHECK)
1355   {
1356     "enable-spelling-feedback-field-trial",
1357     IDS_FLAGS_ENABLE_SPELLING_FEEDBACK_FIELD_TRIAL_NAME,
1358     IDS_FLAGS_ENABLE_SPELLING_FEEDBACK_FIELD_TRIAL_DESCRIPTION,
1359     kOsAll,
1360     SINGLE_VALUE_TYPE(switches::kEnableSpellingFeedbackFieldTrial)
1361   },
1362 #endif
1363   {
1364     "enable-webgl-draft-extensions",
1365     IDS_FLAGS_ENABLE_WEBGL_DRAFT_EXTENSIONS_NAME,
1366     IDS_FLAGS_ENABLE_WEBGL_DRAFT_EXTENSIONS_DESCRIPTION,
1367     kOsAll,
1368     SINGLE_VALUE_TYPE(switches::kEnableWebGLDraftExtensions)
1369   },
1370   {
1371     "enable-web-midi",
1372     IDS_FLAGS_ENABLE_WEB_MIDI_NAME,
1373     IDS_FLAGS_ENABLE_WEB_MIDI_DESCRIPTION,
1374     kOsMac | kOsWin | kOsLinux | kOsCrOS | kOsAndroid,
1375     SINGLE_VALUE_TYPE(switches::kEnableWebMIDI)
1376   },
1377   {
1378     "enable-new-profile-management",
1379     IDS_FLAGS_ENABLE_NEW_PROFILE_MANAGEMENT_NAME,
1380     IDS_FLAGS_ENABLE_NEW_PROFILE_MANAGEMENT_DESCRIPTION,
1381     kOsAndroid | kOsMac | kOsWin | kOsLinux | kOsCrOS,
1382     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableNewProfileManagement,
1383                               switches::kDisableNewProfileManagement)
1384   },
1385   {
1386     "enable-account-consistency",
1387     IDS_FLAGS_ENABLE_ACCOUNT_CONSISTENCY_NAME,
1388     IDS_FLAGS_ENABLE_ACCOUNT_CONSISTENCY_DESCRIPTION,
1389     kOsAndroid | kOsMac | kOsWin | kOsLinux | kOsCrOS,
1390     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableAccountConsistency,
1391                               switches::kDisableAccountConsistency)
1392   },
1393   {
1394     "enable-fast-user-switching",
1395     IDS_FLAGS_ENABLE_FAST_USER_SWITCHING_NAME,
1396     IDS_FLAGS_ENABLE_FAST_USER_SWITCHING_DESCRIPTION,
1397     kOsMac | kOsWin | kOsLinux,
1398     SINGLE_VALUE_TYPE(switches::kFastUserSwitching)
1399   },
1400   {
1401     "enable-new-avatar-menu",
1402     IDS_FLAGS_ENABLE_NEW_AVATAR_MENU_NAME,
1403     IDS_FLAGS_ENABLE_NEW_AVATAR_MENU_DESCRIPTION,
1404     kOsMac | kOsWin | kOsLinux,
1405     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableNewAvatarMenu,
1406                               switches::kDisableNewAvatarMenu)
1407   },
1408   {
1409     "enable-web-based-signin",
1410     IDS_FLAGS_ENABLE_WEB_BASED_SIGNIN_NAME,
1411     IDS_FLAGS_ENABLE_WEB_BASED_SIGNIN_DESCRIPTION,
1412     kOsMac | kOsWin | kOsLinux,
1413     SINGLE_VALUE_TYPE(switches::kEnableWebBasedSignin)
1414   },
1415   {
1416     "enable-webview-based-signin",
1417     IDS_FLAGS_ENABLE_WEBVIEW_BASED_SIGNIN_NAME,
1418     IDS_FLAGS_ENABLE_WEBVIEW_BASED_SIGNIN_DESCRIPTION,
1419     kOsMac | kOsWin | kOsLinux,
1420     SINGLE_VALUE_TYPE(switches::kEnableWebviewBasedSignin)
1421   },
1422   {
1423     "enable-google-profile-info",
1424     IDS_FLAGS_ENABLE_GOOGLE_PROFILE_INFO_NAME,
1425     IDS_FLAGS_ENABLE_GOOGLE_PROFILE_INFO_DESCRIPTION,
1426     kOsMac | kOsWin | kOsLinux,
1427     SINGLE_VALUE_TYPE(switches::kGoogleProfileInfo)
1428   },
1429   {
1430     "reset-app-list-install-state",
1431     IDS_FLAGS_RESET_APP_LIST_INSTALL_STATE_NAME,
1432     IDS_FLAGS_RESET_APP_LIST_INSTALL_STATE_DESCRIPTION,
1433     kOsMac | kOsWin | kOsLinux,
1434     SINGLE_VALUE_TYPE(switches::kResetAppListInstallState)
1435   },
1436 #if defined(ENABLE_APP_LIST)
1437 #if defined(OS_LINUX)
1438   {
1439     // This is compiled out on non-Linux platforms because otherwise it would be
1440     // visible on Win/Mac/CrOS but not on Linux GTK, which would be confusing.
1441     // TODO(mgiuca): Remove the #if when Aura is the default on Linux.
1442     "enable-app-list",
1443     IDS_FLAGS_ENABLE_APP_LIST_NAME,
1444     IDS_FLAGS_ENABLE_APP_LIST_DESCRIPTION,
1445     kOsLinux,
1446     SINGLE_VALUE_TYPE(switches::kEnableAppList)
1447   },
1448 #endif
1449 #if defined(ENABLE_EXTENSIONS)
1450   {
1451     "enable-surface-worker",
1452     IDS_FLAGS_ENABLE_SURFACE_WORKER_NAME,
1453     IDS_FLAGS_ENABLE_SURFACE_WORKER_DESCRIPTION,
1454     kOsDesktop,
1455     SINGLE_VALUE_TYPE(extensions::switches::kEnableSurfaceWorker)
1456   },
1457 #endif
1458   {
1459     "disable-app-list-app-info",
1460     IDS_FLAGS_DISABLE_APP_INFO_IN_APP_LIST,
1461     IDS_FLAGS_DISABLE_APP_INFO_IN_APP_LIST_DESCRIPTION,
1462     kOsLinux | kOsWin | kOsCrOS,
1463     SINGLE_VALUE_TYPE(app_list::switches::kDisableAppInfo)
1464   },
1465   {
1466     "disable-drive-apps-in-app-list",
1467     IDS_FLAGS_DISABLE_DRIVE_APPS_IN_APP_LIST_NAME,
1468     IDS_FLAGS_DISABLE_DRIVE_APPS_IN_APP_LIST_DESCRIPTION,
1469     kOsCrOS,
1470     SINGLE_VALUE_TYPE(app_list::switches::kDisableDriveAppsInAppList)
1471   },
1472 #endif
1473 #if defined(OS_ANDROID)
1474   {
1475     "enable-accessibility-tab-switcher",
1476     IDS_FLAGS_ENABLE_ACCESSIBILITY_TAB_SWITCHER_NAME,
1477     IDS_FLAGS_ENABLE_ACCESSIBILITY_TAB_SWITCHER_DESCRIPTION,
1478     kOsAndroid,
1479     SINGLE_VALUE_TYPE(switches::kEnableAccessibilityTabSwitcher)
1480   },
1481   {
1482     // TODO(dmazzoni): remove this flag when native android accessibility
1483     // ships in the stable channel. http://crbug.com/356775
1484     "enable-accessibility-script-injection",
1485     IDS_FLAGS_ENABLE_ACCESSIBILITY_SCRIPT_INJECTION_NAME,
1486     IDS_FLAGS_ENABLE_ACCESSIBILITY_SCRIPT_INJECTION_DESCRIPTION,
1487     kOsAndroid,
1488     // Java-only switch: ContentSwitches.ENABLE_ACCESSIBILITY_SCRIPT_INJECTION.
1489     SINGLE_VALUE_TYPE("enable-accessibility-script-injection")
1490   },
1491 #endif
1492   {
1493     "enable-one-copy",
1494     IDS_FLAGS_ONE_COPY_NAME,
1495     IDS_FLAGS_ONE_COPY_DESCRIPTION,
1496     kOsAll,
1497     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableOneCopy,
1498                               switches::kDisableOneCopy)
1499   },
1500   {
1501     "enable-zero-copy",
1502     IDS_FLAGS_ZERO_COPY_NAME,
1503     IDS_FLAGS_ZERO_COPY_DESCRIPTION,
1504     kOsAll,
1505     SINGLE_VALUE_TYPE(switches::kEnableZeroCopy)
1506   },
1507 #if defined(OS_CHROMEOS)
1508   {
1509     "enable-first-run-ui-transitions",
1510     IDS_FLAGS_ENABLE_FIRST_RUN_UI_TRANSITIONS_NAME,
1511     IDS_FLAGS_ENABLE_FIRST_RUN_UI_TRANSITIONS_DESCRIPTION,
1512     kOsCrOS,
1513     SINGLE_VALUE_TYPE(chromeos::switches::kEnableFirstRunUITransitions)
1514   },
1515 #endif
1516   {
1517     "disable-new-bookmark-apps",
1518     IDS_FLAGS_DISABLE_NEW_BOOKMARK_APPS_NAME,
1519     IDS_FLAGS_DISABLE_NEW_BOOKMARK_APPS_DESCRIPTION,
1520     kOsWin | kOsCrOS | kOsLinux | kOsMac,
1521     SINGLE_VALUE_TYPE(switches::kDisableNewBookmarkApps)
1522   },
1523 #if defined(OS_MACOSX)
1524   {
1525     "enable-hosted-app-shim-creation",
1526     IDS_FLAGS_ENABLE_HOSTED_APP_SHIM_CREATION_NAME,
1527     IDS_FLAGS_ENABLE_HOSTED_APP_SHIM_CREATION_DESCRIPTION,
1528     kOsMac,
1529     SINGLE_VALUE_TYPE(switches::kEnableHostedAppShimCreation)
1530   },
1531   {
1532     "enable-hosted-app-quit-notification",
1533     IDS_FLAGS_ENABLE_HOSTED_APP_QUIT_NOTIFICATION_NAME,
1534     IDS_FLAGS_ENABLE_HOSTED_APP_QUIT_NOTIFICATION_DESCRIPTION,
1535     kOsMac,
1536     SINGLE_VALUE_TYPE(switches::kHostedAppQuitNotification)
1537   },
1538 #endif
1539   {
1540     "enable-ephemeral-apps-in-webstore",
1541     IDS_FLAGS_ENABLE_EPHEMERAL_APPS_IN_WEBSTORE_NAME,
1542     IDS_FLAGS_ENABLE_EPHEMERAL_APPS_IN_WEBSTORE_DESCRIPTION,
1543     kOsAll,
1544     SINGLE_VALUE_TYPE(switches::kEnableEphemeralAppsInWebstore)
1545   },
1546   {
1547     "enable-linkable-ephemeral-apps",
1548     IDS_FLAGS_ENABLE_LINKABLE_EPHEMERAL_APPS_NAME,
1549     IDS_FLAGS_ENABLE_LINKABLE_EPHEMERAL_APPS_DESCRIPTION,
1550     kOsAll,
1551     SINGLE_VALUE_TYPE(switches::kEnableLinkableEphemeralApps)
1552   },
1553   {
1554     "enable-service-worker-sync",
1555     IDS_FLAGS_ENABLE_SERVICE_WORKER_SYNC_NAME,
1556     IDS_FLAGS_ENABLE_SERVICE_WORKER_SYNC_DESCRIPTION,
1557     kOsAll,
1558     SINGLE_VALUE_TYPE(switches::kEnableServiceWorkerSync)
1559   },
1560 #if defined(OS_ANDROID)
1561   {
1562     "disable-click-delay",
1563     IDS_FLAGS_DISABLE_CLICK_DELAY_NAME,
1564     IDS_FLAGS_DISABLE_CLICK_DELAY_DESCRIPTION,
1565     kOsAndroid,
1566     // Java-only switch: CommandLine.DISABLE_CLICK_DELAY
1567     SINGLE_VALUE_TYPE("disable-click-delay")
1568   },
1569   {
1570     "disable-pull-to-refresh-effect",
1571     IDS_FLAGS_DISABLE_PULL_TO_REFRESH_EFFECT_NAME,
1572     IDS_FLAGS_DISABLE_PULL_TO_REFRESH_EFFECT_DESCRIPTION,
1573     kOsAndroid,
1574     SINGLE_VALUE_TYPE(switches::kDisablePullToRefreshEffect)
1575   },
1576 #endif
1577 #if defined(OS_MACOSX)
1578   {
1579     "enable-translate-new-ux",
1580     IDS_FLAGS_ENABLE_TRANSLATE_NEW_UX_NAME,
1581     IDS_FLAGS_ENABLE_TRANSLATE_NEW_UX_DESCRIPTION,
1582     kOsMac,
1583     SINGLE_VALUE_TYPE(switches::kEnableTranslateNewUX)
1584   },
1585 #endif
1586 #if defined(TOOLKIT_VIEWS)
1587   {
1588     "disable-views-rect-based-targeting",  // FLAGS:RECORD_UMA
1589     IDS_FLAGS_DISABLE_VIEWS_RECT_BASED_TARGETING_NAME,
1590     IDS_FLAGS_DISABLE_VIEWS_RECT_BASED_TARGETING_DESCRIPTION,
1591     kOsCrOS | kOsWin | kOsLinux,
1592     SINGLE_VALUE_TYPE(views::switches::kDisableViewsRectBasedTargeting)
1593   },
1594   {
1595     "enable-link-disambiguation-popup",
1596     IDS_FLAGS_ENABLE_LINK_DISAMBIGUATION_POPUP_NAME,
1597     IDS_FLAGS_ENABLE_LINK_DISAMBIGUATION_POPUP_DESCRIPTION,
1598     kOsCrOS | kOsWin,
1599     SINGLE_VALUE_TYPE(switches::kEnableLinkDisambiguationPopup)
1600   },
1601 #endif
1602 #if defined(ENABLE_EXTENSIONS)
1603   {
1604     "enable-apps-show-on-first-paint",
1605     IDS_FLAGS_ENABLE_APPS_SHOW_ON_FIRST_PAINT_NAME,
1606     IDS_FLAGS_ENABLE_APPS_SHOW_ON_FIRST_PAINT_DESCRIPTION,
1607     kOsDesktop,
1608     SINGLE_VALUE_TYPE(extensions::switches::kEnableAppsShowOnFirstPaint)
1609   },
1610 #endif
1611   {
1612     "enhanced-bookmarks-experiment",
1613     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_NAME,
1614     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_DESCRIPTION,
1615     kOsDesktop | kOsAndroid,
1616     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(
1617         switches::kEnhancedBookmarksExperiment, "1",
1618         switches::kEnhancedBookmarksExperiment, "0")
1619   },
1620   {
1621     "manual-enhanced-bookmarks",
1622     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_NAME,
1623     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_DESCRIPTION,
1624     kOsDesktop | kOsAndroid,
1625     SINGLE_VALUE_TYPE(switches::kManualEnhancedBookmarks)
1626   },
1627   {
1628     "manual-enhanced-bookmarks-optout",
1629     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_NAME,
1630     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_DESCRIPTION,
1631     kOsDesktop | kOsAndroid,
1632     SINGLE_VALUE_TYPE(switches::kManualEnhancedBookmarksOptout)
1633   },
1634 #if defined(OS_ANDROID)
1635   {
1636     "enable-zero-suggest-experiment",
1637     IDS_FLAGS_ZERO_SUGGEST_EXPERIMENT_NAME,
1638     IDS_FLAGS_ZERO_SUGGEST_EXPERIMENT_DESCRIPTION,
1639     kOsAndroid,
1640     MULTI_VALUE_TYPE(kZeroSuggestExperimentsChoices)
1641   },
1642   {
1643     "enable-reader-mode-toolbar-icon",
1644     IDS_FLAGS_READER_MODE_EXPERIMENT_NAME,
1645     IDS_FLAGS_READER_MODE_EXPERIMENT_DESCRIPTION,
1646     kOsAndroid,
1647     SINGLE_VALUE_TYPE(switches::kEnableReaderModeToolbarIcon)
1648   },
1649 #endif
1650   {
1651     "num-raster-threads",
1652     IDS_FLAGS_NUM_RASTER_THREADS_NAME,
1653     IDS_FLAGS_NUM_RASTER_THREADS_DESCRIPTION,
1654     kOsAll,
1655     MULTI_VALUE_TYPE(kNumRasterThreadsChoices)
1656   },
1657   {
1658     "origin-chip-in-omnibox",
1659     IDS_FLAGS_ORIGIN_CHIP_NAME,
1660     IDS_FLAGS_ORIGIN_CHIP_DESCRIPTION,
1661     kOsCrOS | kOsMac | kOsWin | kOsLinux,
1662     MULTI_VALUE_TYPE(kOriginChipChoices)
1663   },
1664   {
1665     "search-button-in-omnibox",
1666     IDS_FLAGS_SEARCH_BUTTON_IN_OMNIBOX_NAME,
1667     IDS_FLAGS_SEARCH_BUTTON_IN_OMNIBOX_DESCRIPTION,
1668     kOsCrOS | kOsMac | kOsWin | kOsLinux,
1669     MULTI_VALUE_TYPE(kSearchButtonInOmniboxChoices)
1670   },
1671   {
1672     "ignore-autocomplete-off-autofill",
1673     IDS_FLAGS_IGNORE_AUTOCOMPLETE_OFF_AUTOFILL_NAME,
1674     IDS_FLAGS_IGNORE_AUTOCOMPLETE_OFF_AUTOFILL_DESCRIPTION,
1675     kOsCrOS | kOsMac | kOsWin | kOsLinux,
1676     ENABLE_DISABLE_VALUE_TYPE(
1677         autofill::switches::kIgnoreAutocompleteOffForAutofill,
1678         autofill::switches::kRespectAutocompleteOffForAutofill)
1679   },
1680   {
1681     "enable-single-click-autofill",
1682     IDS_FLAGS_ENABLE_SINGLE_CLICK_AUTOFILL_NAME,
1683     IDS_FLAGS_ENABLE_SINGLE_CLICK_AUTOFILL_DESCRIPTION,
1684     kOsCrOS | kOsMac | kOsWin | kOsLinux | kOsAndroid,
1685     ENABLE_DISABLE_VALUE_TYPE(
1686         autofill::switches::kEnableSingleClickAutofill,
1687         autofill::switches::kDisableSingleClickAutofill)
1688   },
1689   {
1690     "enable-wallet-card-import",
1691     IDS_FLAGS_ENABLE_WALLET_CARD_IMPORT_NAME,
1692     IDS_FLAGS_ENABLE_WALLET_CARD_IMPORT_DESCRIPTION,
1693     kOsCrOS | kOsWin | kOsLinux | kOsAndroid,
1694     SINGLE_VALUE_TYPE(autofill::switches::kEnableWalletCardImport)
1695   },
1696   {
1697     "enable-permissions-bubbles",
1698     IDS_FLAGS_ENABLE_PERMISSIONS_BUBBLES_NAME,
1699     IDS_FLAGS_ENABLE_PERMISSIONS_BUBBLES_DESCRIPTION,
1700     kOsCrOS | kOsMac | kOsWin | kOsLinux,
1701     ENABLE_DISABLE_VALUE_TYPE(switches::kEnablePermissionsBubbles,
1702                               switches::kDisablePermissionsBubbles)
1703   },
1704   {
1705     "enable-session-crashed-bubble",
1706     IDS_FLAGS_ENABLE_SESSION_CRASHED_BUBBLE_NAME,
1707     IDS_FLAGS_ENABLE_SESSION_CRASHED_BUBBLE_DESCRIPTION,
1708     kOsWin | kOsLinux,
1709     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSessionCrashedBubble,
1710                               switches::kDisableSessionCrashedBubble)
1711   },
1712   {
1713     "enable-out-of-process-pdf",
1714     IDS_FLAGS_OUT_OF_PROCESS_PDF_NAME,
1715     IDS_FLAGS_OUT_OF_PROCESS_PDF_DESCRIPTION,
1716     kOsDesktop,
1717     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableOutOfProcessPdf,
1718                               switches::kDisableOutOfProcessPdf)
1719   },
1720   {
1721     "disable-cast-streaming-hw-encoding",
1722     IDS_FLAGS_DISABLE_CAST_STREAMING_HW_ENCODING_NAME,
1723     IDS_FLAGS_DISABLE_CAST_STREAMING_HW_ENCODING_DESCRIPTION,
1724     kOsAll,
1725     SINGLE_VALUE_TYPE(switches::kDisableCastStreamingHWEncoding)
1726   },
1727 #if defined(OS_ANDROID)
1728   {
1729     "disable-cast",
1730     IDS_FLAGS_DISABLE_CAST_NAME,
1731     IDS_FLAGS_DISABLE_CAST_DESCRIPTION,
1732     kOsAndroid,
1733     SINGLE_VALUE_TYPE(switches::kDisableCast)
1734   },
1735   {
1736     "prefetch-search-results",
1737     IDS_FLAGS_PREFETCH_SEARCH_RESULTS_NAME,
1738     IDS_FLAGS_PREFETCH_SEARCH_RESULTS_DESCRIPTION,
1739     kOsAndroid,
1740     SINGLE_VALUE_TYPE(switches::kPrefetchSearchResults)
1741   },
1742 #endif
1743 #if defined(ENABLE_APP_LIST)
1744   {
1745     "enable-experimental-app-list",
1746     IDS_FLAGS_ENABLE_EXPERIMENTAL_APP_LIST_NAME,
1747     IDS_FLAGS_ENABLE_EXPERIMENTAL_APP_LIST_DESCRIPTION,
1748     kOsWin | kOsLinux | kOsCrOS,
1749     ENABLE_DISABLE_VALUE_TYPE(app_list::switches::kEnableExperimentalAppList,
1750                               app_list::switches::kDisableExperimentalAppList)
1751   },
1752   {
1753     "enable-centered-app-list",
1754     IDS_FLAGS_ENABLE_CENTERED_APP_LIST_NAME,
1755     IDS_FLAGS_ENABLE_CENTERED_APP_LIST_DESCRIPTION,
1756     kOsWin | kOsLinux | kOsCrOS,
1757     SINGLE_VALUE_TYPE(app_list::switches::kEnableCenteredAppList)
1758   },
1759 #endif
1760   {
1761     "touch-scrolling-mode",
1762     IDS_FLAGS_TOUCH_SCROLLING_MODE_NAME,
1763     IDS_FLAGS_TOUCH_SCROLLING_MODE_DESCRIPTION,
1764     kOsWin | kOsLinux | kOsCrOS | kOsAndroid,
1765     MULTI_VALUE_TYPE(kTouchScrollingModeChoices)
1766   },
1767   {
1768     "disable-threaded-scrolling",
1769     IDS_FLAGS_DISABLE_THREADED_SCROLLING_NAME,
1770     IDS_FLAGS_DISABLE_THREADED_SCROLLING_DESCRIPTION,
1771     kOsWin | kOsLinux | kOsCrOS | kOsAndroid,
1772     SINGLE_VALUE_TYPE(switches::kDisableThreadedScrolling)
1773   },
1774   {
1775     "bleeding-edge-renderer-mode",
1776     IDS_FLAGS_BLEEDING_RENDERER_NAME,
1777     IDS_FLAGS_BLEEDING_RENDERER_DESCRIPTION,
1778     kOsAndroid,
1779     SINGLE_VALUE_TYPE(switches::kEnableBleedingEdgeRenderingFastPaths)
1780   },
1781   {
1782     "enable-settings-window",
1783     IDS_FLAGS_ENABLE_SETTINGS_WINDOW_NAME,
1784     IDS_FLAGS_ENABLE_SETTINGS_WINDOW_DESCRIPTION,
1785     kOsDesktop,
1786     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSettingsWindow,
1787                               switches::kDisableSettingsWindow)
1788   },
1789 #if defined(OS_ANDROID)
1790   {
1791     "enable-instant-search-clicks",
1792     IDS_FLAGS_ENABLE_INSTANT_SEARCH_CLICKS_NAME,
1793     IDS_FLAGS_ENABLE_INSTANT_SEARCH_CLICKS_DESCRIPTION,
1794     kOsAndroid,
1795     SINGLE_VALUE_TYPE(switches::kEnableInstantSearchClicks)
1796   },
1797 #endif
1798   {
1799     "enable-save-password-bubble",
1800     IDS_FLAGS_ENABLE_SAVE_PASSWORD_BUBBLE_NAME,
1801     IDS_FLAGS_ENABLE_SAVE_PASSWORD_BUBBLE_DESCRIPTION,
1802     kOsWin | kOsLinux | kOsCrOS | kOsMac,
1803     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSavePasswordBubble,
1804                               switches::kDisableSavePasswordBubble)
1805   },
1806   // TODO(tyoshino): Remove this temporary flag and command line switch. See
1807   // crbug.com/366483 for the target milestone.
1808   {
1809     "allow-insecure-websocket-from-https-origin",
1810     IDS_FLAGS_ALLOW_INSECURE_WEBSOCKET_FROM_HTTPS_ORIGIN_NAME,
1811     IDS_FLAGS_ALLOW_INSECURE_WEBSOCKET_FROM_HTTPS_ORIGIN_DESCRIPTION,
1812     kOsAll,
1813     SINGLE_VALUE_TYPE(switches::kAllowInsecureWebSocketFromHttpsOrigin)
1814   },
1815   {
1816     "enable-apps-file-associations",
1817     IDS_FLAGS_ENABLE_APPS_FILE_ASSOCIATIONS_NAME,
1818     IDS_FLAGS_ENABLE_APPS_FILE_ASSOCIATIONS_DESCRIPTION,
1819     kOsMac,
1820     SINGLE_VALUE_TYPE(switches::kEnableAppsFileAssociations)
1821   },
1822 #if defined(OS_ANDROID)
1823   {
1824     "enable-embeddedsearch-api",
1825     IDS_FLAGS_ENABLE_EMBEDDEDSEARCH_API_NAME,
1826     IDS_FLAGS_ENABLE_EMBEDDEDSEARCH_API_DESCRIPTION,
1827     kOsAndroid,
1828     SINGLE_VALUE_TYPE(switches::kEnableEmbeddedSearchAPI)
1829   },
1830   {
1831     "enable-app-install-alerts",
1832     IDS_FLAGS_ENABLE_APP_INSTALL_ALERTS_NAME,
1833     IDS_FLAGS_ENABLE_APP_INSTALL_ALERTS_DESCRIPTION,
1834     kOsAndroid,
1835     SINGLE_VALUE_TYPE(switches::kEnableAppInstallAlerts)
1836   },
1837 #endif
1838   {
1839     "distance-field-text",
1840     IDS_FLAGS_DISTANCE_FIELD_TEXT_NAME,
1841     IDS_FLAGS_DISTANCE_FIELD_TEXT_DESCRIPTION,
1842     kOsAll,
1843     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableDistanceFieldText,
1844                               switches::kDisableDistanceFieldText)
1845   },
1846   {
1847     "extension-content-verification",
1848     IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_NAME,
1849     IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_DESCRIPTION,
1850     kOsDesktop,
1851     MULTI_VALUE_TYPE(kExtensionContentVerificationChoices)
1852   },
1853 #if defined(USE_AURA)
1854   {
1855     "text-input-focus-manager",
1856     IDS_FLAGS_TEXT_INPUT_FOCUS_MANAGER_NAME,
1857     IDS_FLAGS_TEXT_INPUT_FOCUS_MANAGER_DESCRIPTION,
1858     kOsCrOS | kOsLinux | kOsWin,
1859     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableTextInputFocusManager,
1860                               switches::kDisableTextInputFocusManager)
1861   },
1862 #endif
1863 #if defined(ENABLE_EXTENSIONS)
1864   {
1865     "extension-active-script-permission",
1866     IDS_FLAGS_USER_CONSENT_FOR_EXTENSION_SCRIPTS_NAME,
1867     IDS_FLAGS_USER_CONSENT_FOR_EXTENSION_SCRIPTS_DESCRIPTION,
1868     kOsAll,
1869     SINGLE_VALUE_TYPE(extensions::switches::kEnableScriptsRequireAction)
1870   },
1871 #endif
1872   {
1873     "harfbuzz-rendertext",
1874     IDS_FLAGS_HARFBUZZ_RENDERTEXT_NAME,
1875     IDS_FLAGS_HARFBUZZ_RENDERTEXT_DESCRIPTION,
1876     kOsDesktop,
1877     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableHarfBuzzRenderText,
1878                               switches::kDisableHarfBuzzRenderText)
1879   },
1880 #if defined(OS_ANDROID)
1881   {
1882     "answers-in-suggest",
1883     IDS_FLAGS_ENABLE_ANSWERS_IN_SUGGEST_NAME,
1884     IDS_FLAGS_ENABLE_ANSWERS_IN_SUGGEST_DESCRIPTION,
1885     kOsAndroid,
1886     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableAnswersInSuggest,
1887                               switches::kDisableAnswersInSuggest)
1888   },
1889 #endif
1890 #if defined(OS_ANDROID)
1891   {
1892     "enable-data-reduction-proxy-dev",
1893     IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_DEV_NAME,
1894     IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_DEV_DESCRIPTION,
1895     kOsAndroid,
1896     ENABLE_DISABLE_VALUE_TYPE(
1897         data_reduction_proxy::switches::kEnableDataReductionProxyDev,
1898         data_reduction_proxy::switches::kDisableDataReductionProxyDev)
1899   },
1900   {
1901     "enable-data-reduction-proxy-alt",
1902     IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_ALTERNATIVE_NAME,
1903     IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_ALTERNATIVE_DESCRIPTION,
1904     kOsAndroid,
1905     SINGLE_VALUE_TYPE(
1906         data_reduction_proxy::switches::kEnableDataReductionProxyAlt)
1907   },
1908 #endif
1909   {
1910     "disable-experimental-hotwording",
1911     IDS_FLAGS_DISABLE_EXPERIMENTAL_HOTWORDING_NAME,
1912     IDS_FLAGS_DISABLE_EXPERIMENTAL_HOTWORDING_DESCRIPTION,
1913     kOsDesktop,
1914     SINGLE_VALUE_TYPE(switches::kDisableExperimentalHotwording)
1915   },
1916   {
1917     "enable-hotword-hardware",
1918     IDS_FLAGS_ENABLE_EXPERIMENTAL_HOTWORD_HARDWARE_NAME,
1919     IDS_FLAGS_ENABLE_EXPERIMENTAL_HOTWORD_HARDWARE_DESCRIPTION,
1920     kOsCrOS,
1921     SINGLE_VALUE_TYPE(switches::kEnableExperimentalHotwordHardware)
1922   },
1923 #if defined(ENABLE_EXTENSIONS)
1924   {
1925     "enable-embedded-extension-options",
1926     IDS_FLAGS_ENABLE_EMBEDDED_EXTENSION_OPTIONS_NAME,
1927     IDS_FLAGS_ENABLE_EMBEDDED_EXTENSION_OPTIONS_DESCRIPTION,
1928     kOsDesktop,
1929     SINGLE_VALUE_TYPE(extensions::switches::kEnableEmbeddedExtensionOptions)
1930   },
1931 #endif
1932 #if defined(USE_ASH)
1933   {
1934     "enable-web-app-frame",
1935     IDS_FLAGS_ENABLE_WEB_APP_FRAME_NAME,
1936     IDS_FLAGS_ENABLE_WEB_APP_FRAME_DESCRIPTION,
1937     kOsWin | kOsCrOS,
1938     SINGLE_VALUE_TYPE(switches::kEnableWebAppFrame)
1939   },
1940 #endif
1941   {
1942     "enable-website-settings-manager",
1943     IDS_FLAGS_ENABLE_WEBSITE_SETTINGS_NAME,
1944     IDS_FLAGS_ENABLE_WEBSITE_SETTINGS_DESCRIPTION,
1945     kOsDesktop,
1946     SINGLE_VALUE_TYPE(switches::kEnableWebsiteSettingsManager)
1947   },
1948   {
1949     "remember-cert-error-decisions",
1950     IDS_FLAGS_REMEMBER_CERTIFICATE_ERROR_DECISIONS_NAME,
1951     IDS_FLAGS_REMEMBER_CERTIFICATE_ERROR_DECISIONS_DESCRIPTION,
1952     kOsAll,
1953     MULTI_VALUE_TYPE(kRememberCertificateErrorDecisionsChoices)
1954   },
1955   {
1956     "enable-drop-sync-credential",
1957     IDS_FLAGS_ENABLE_DROP_SYNC_CREDENTIAL_NAME,
1958     IDS_FLAGS_ENABLE_DROP_SYNC_CREDENTIAL_DESCRIPTION,
1959     kOsAll,
1960     ENABLE_DISABLE_VALUE_TYPE(
1961         password_manager::switches::kEnableDropSyncCredential,
1962         password_manager::switches::kDisableDropSyncCredential)
1963   },
1964 #if defined(ENABLE_EXTENSIONS)
1965   {
1966     "enable-extension-action-redesign",
1967     IDS_FLAGS_ENABLE_EXTENSION_ACTION_REDESIGN_NAME,
1968     IDS_FLAGS_ENABLE_EXTENSION_ACTION_REDESIGN_DESCRIPTION,
1969     kOsWin | kOsLinux | kOsCrOS,
1970     SINGLE_VALUE_TYPE(extensions::switches::kEnableExtensionActionRedesign)
1971   },
1972 #endif
1973   {
1974     "autofill-sync-credential",
1975     IDS_FLAGS_AUTOFILL_SYNC_CREDENTIAL_NAME,
1976     IDS_FLAGS_AUTOFILL_SYNC_CREDENTIAL_DESCRIPTION,
1977     kOsAll,
1978     MULTI_VALUE_TYPE(kAutofillSyncCredentialChoices)
1979   },
1980 #if !defined(OS_ANDROID)
1981   {
1982     "enable-message-center-always-scroll-up-upon-notification-removal",
1983     IDS_FLAGS_ENABLE_MESSAGE_CENTER_ALWAYS_SCROLL_UP_UPON_REMOVAL_NAME,
1984     IDS_FLAGS_ENABLE_MESSAGE_CENTER_ALWAYS_SCROLL_UP_UPON_REMOVAL_DESCRIPTION,
1985     kOsDesktop,
1986     SINGLE_VALUE_TYPE(
1987         switches::kEnableMessageCenterAlwaysScrollUpUponNotificationRemoval)
1988   },
1989 #endif
1990 #if defined(OS_CHROMEOS)
1991   {
1992     "use-memory-pressure-chromeos",
1993     IDS_FLAGS_USE_MEMORY_PRESSURE_NAME,
1994     IDS_FLAGS_USE_MEMORY_PRESSURE_DESCRIPTION,
1995     kOsCrOS,
1996     SINGLE_VALUE_TYPE(chromeos::switches::kUseMemoryPressureSystemChromeOS)
1997   },
1998   {
1999     "wake-on-packets",
2000     IDS_FLAGS_WAKE_ON_PACKETS_NAME,
2001     IDS_FLAGS_WAKE_ON_PACKETS_DESCRIPTION,
2002     kOsCrOSOwnerOnly,
2003     SINGLE_VALUE_TYPE(chromeos::switches::kWakeOnPackets)
2004   },
2005 #endif  // OS_CHROMEOS
2006   {
2007     "enable-tab-audio-muting",
2008     IDS_FLAGS_ENABLE_TAB_AUDIO_MUTING_NAME,
2009     IDS_FLAGS_ENABLE_TAB_AUDIO_MUTING_DESCRIPTION,
2010     kOsDesktop,
2011     SINGLE_VALUE_TYPE(switches::kEnableTabAudioMuting)
2012   },
2013   {
2014     "enable-credential-manager-api",
2015     IDS_FLAGS_CREDENTIAL_MANAGER_API_NAME,
2016     IDS_FLAGS_CREDENTIAL_MANAGER_API_DESCRIPTION,
2017     kOsAll,
2018     SINGLE_VALUE_TYPE(switches::kEnableCredentialManagerAPI)
2019   },
2020   {
2021     "reduced-referrer-granularity",
2022     IDS_FLAGS_REDUCED_REFERRER_GRANULARITY_NAME,
2023     IDS_FLAGS_REDUCED_REFERRER_GRANULARITY_DESCRIPTION,
2024     kOsAll,
2025     SINGLE_VALUE_TYPE(switches::kReducedReferrerGranularity)
2026   },
2027 #if defined(ENABLE_PLUGINS)
2028   {
2029     "enable-plugin-power-saver",
2030     IDS_FLAGS_ENABLE_PLUGIN_POWER_SAVER_NAME,
2031     IDS_FLAGS_ENABLE_PLUGIN_POWER_SAVER_DESCRIPTION,
2032     kOsDesktop,
2033     SINGLE_VALUE_TYPE(switches::kEnablePluginPowerSaver)
2034   },
2035 #endif
2036 #if defined(OS_CHROMEOS)
2037   {
2038     "disable-new-zip-unpacker",
2039     IDS_FLAGS_DISABLE_NEW_ZIP_UNPACKER_NAME,
2040     IDS_FLAGS_DISABLE_NEW_ZIP_UNPACKER_DESCRIPTION,
2041     kOsCrOS,
2042     SINGLE_VALUE_TYPE(chromeos::switches::kDisableNewZIPUnpacker)
2043   },
2044 #endif  // defined(OS_CHROMEOS)
2045   {
2046     "ssl-version-min",
2047     IDS_FLAGS_SSL_VERSION_MIN_NAME,
2048     IDS_FLAGS_SSL_VERSION_MIN_DESCRIPTION,
2049     kOsAll,
2050     MULTI_VALUE_TYPE(kSSLVersionMinChoices)
2051   },
2052   {
2053     "enable-credit-card-scan",
2054     IDS_FLAGS_ENABLE_CREDIT_CARD_SCAN_NAME,
2055     IDS_FLAGS_ENABLE_CREDIT_CARD_SCAN_DESCRIPTION,
2056     kOsAndroid,
2057     ENABLE_DISABLE_VALUE_TYPE(autofill::switches::kEnableCreditCardScan,
2058                               autofill::switches::kDisableCreditCardScan)
2059   },
2060 #if defined(OS_CHROMEOS)
2061   {
2062     "enable-captive-portal-bypass-proxy",
2063     IDS_FLAGS_ENABLE_CAPTIVE_PORTAL_BYPASS_PROXY_NAME,
2064     IDS_FLAGS_ENABLE_CAPTIVE_PORTAL_BYPASS_PROXY_DESCRIPTION,
2065     kOsCrOS,
2066     SINGLE_VALUE_TYPE(chromeos::switches::kEnableCaptivePortalBypassProxy)
2067   },
2068   {
2069     "enable-roboto-font-ui",
2070     IDS_FLAGS_ENABLE_ROBOTO_FONT_UI_NAME,
2071     IDS_FLAGS_ENABLE_ROBOTO_FONT_UI_DESCRIPTION,
2072     kOsCrOS,
2073     SINGLE_VALUE_TYPE(switches::kEnableRobotoFontUI)
2074   },
2075 #endif  // defined(OS_CHROMEOS)
2076 #if defined(OS_ANDROID)
2077   {
2078     "enable-seccomp-filter-sandbox",
2079     IDS_FLAGS_ENABLE_SECCOMP_FILTER_SANDBOX_ANDROID_NAME,
2080     IDS_FLAGS_ENABLE_SECCOMP_FILTER_SANDBOX_ANDROID_DESCRIPTION,
2081     kOsAndroid,
2082     SINGLE_VALUE_TYPE(switches::kEnableSeccompFilterSandbox)
2083   },
2084 #endif
2085   {
2086     "enable-touch-hover",
2087     IDS_FLAGS_ENABLE_TOUCH_HOVER_NAME,
2088     IDS_FLAGS_ENABLE_TOUCH_HOVER_DESCRIPTION,
2089     kOsAndroid,
2090     SINGLE_VALUE_TYPE("enable-touch-hover")
2091   },
2092   {
2093     "enable-fill-on-account-select",
2094     IDS_FILL_ON_ACCOUNT_SELECT_NAME,
2095     IDS_FILL_ON_ACCOUNT_SELECT_DESCRIPTION,
2096     kOsAll,
2097     MULTI_VALUE_TYPE(kFillOnAccountSelectChoices)
2098   },
2099
2100   // NOTE: Adding new command-line switches requires adding corresponding
2101   // entries to enum "LoginCustomFlags" in histograms.xml. See note in
2102   // histograms.xml and don't forget to run AboutFlagsHistogramTest unit test.
2103 };
2104
2105 const Experiment* experiments = kExperiments;
2106 size_t num_experiments = arraysize(kExperiments);
2107
2108 // Stores and encapsulates the little state that about:flags has.
2109 class FlagsState {
2110  public:
2111   FlagsState() : needs_restart_(false) {}
2112   void ConvertFlagsToSwitches(FlagsStorage* flags_storage,
2113                               base::CommandLine* command_line,
2114                               SentinelsMode sentinels);
2115   bool IsRestartNeededToCommitChanges();
2116   void SetExperimentEnabled(
2117       FlagsStorage* flags_storage,
2118       const std::string& internal_name,
2119       bool enable);
2120   void RemoveFlagsSwitches(
2121       std::map<std::string, base::CommandLine::StringType>* switch_list);
2122   void ResetAllFlags(FlagsStorage* flags_storage);
2123   void reset();
2124
2125   // Returns the singleton instance of this class
2126   static FlagsState* GetInstance() {
2127     return Singleton<FlagsState>::get();
2128   }
2129
2130  private:
2131   bool needs_restart_;
2132   std::map<std::string, std::string> flags_switches_;
2133
2134   DISALLOW_COPY_AND_ASSIGN(FlagsState);
2135 };
2136
2137 // Adds the internal names for the specified experiment to |names|.
2138 void AddInternalName(const Experiment& e, std::set<std::string>* names) {
2139   if (e.type == Experiment::SINGLE_VALUE) {
2140     names->insert(e.internal_name);
2141   } else {
2142     DCHECK(e.type == Experiment::MULTI_VALUE ||
2143            e.type == Experiment::ENABLE_DISABLE_VALUE);
2144     for (int i = 0; i < e.num_choices; ++i)
2145       names->insert(e.NameForChoice(i));
2146   }
2147 }
2148
2149 // Confirms that an experiment is valid, used in a DCHECK in
2150 // SanitizeList below.
2151 bool ValidateExperiment(const Experiment& e) {
2152   switch (e.type) {
2153     case Experiment::SINGLE_VALUE:
2154       DCHECK_EQ(0, e.num_choices);
2155       DCHECK(!e.choices);
2156       break;
2157     case Experiment::MULTI_VALUE:
2158       DCHECK_GT(e.num_choices, 0);
2159       DCHECK(e.choices);
2160       DCHECK(e.choices[0].command_line_switch);
2161       DCHECK_EQ('\0', e.choices[0].command_line_switch[0]);
2162       break;
2163     case Experiment::ENABLE_DISABLE_VALUE:
2164       DCHECK_EQ(3, e.num_choices);
2165       DCHECK(!e.choices);
2166       DCHECK(e.command_line_switch);
2167       DCHECK(e.command_line_value);
2168       DCHECK(e.disable_command_line_switch);
2169       DCHECK(e.disable_command_line_value);
2170       break;
2171     default:
2172       NOTREACHED();
2173   }
2174   return true;
2175 }
2176
2177 // Removes all experiments from prefs::kEnabledLabsExperiments that are
2178 // unknown, to prevent this list to become very long as experiments are added
2179 // and removed.
2180 void SanitizeList(FlagsStorage* flags_storage) {
2181   std::set<std::string> known_experiments;
2182   for (size_t i = 0; i < num_experiments; ++i) {
2183     DCHECK(ValidateExperiment(experiments[i]));
2184     AddInternalName(experiments[i], &known_experiments);
2185   }
2186
2187   std::set<std::string> enabled_experiments = flags_storage->GetFlags();
2188
2189   std::set<std::string> new_enabled_experiments =
2190       base::STLSetIntersection<std::set<std::string> >(
2191           known_experiments, enabled_experiments);
2192
2193   if (new_enabled_experiments != enabled_experiments)
2194     flags_storage->SetFlags(new_enabled_experiments);
2195 }
2196
2197 void GetSanitizedEnabledFlags(
2198     FlagsStorage* flags_storage, std::set<std::string>* result) {
2199   SanitizeList(flags_storage);
2200   *result = flags_storage->GetFlags();
2201 }
2202
2203 bool SkipConditionalExperiment(const Experiment& experiment,
2204                                FlagsStorage* flags_storage) {
2205   if ((experiment.internal_name == std::string("manual-enhanced-bookmarks")) ||
2206       (experiment.internal_name ==
2207            std::string("manual-enhanced-bookmarks-optout"))) {
2208     return true;
2209   }
2210
2211 #if defined(OS_ANDROID)
2212   // enable-data-reduction-proxy-dev is only available for the Dev/Beta channel.
2213   if (!strcmp("enable-data-reduction-proxy-dev", experiment.internal_name) &&
2214       chrome::VersionInfo::GetChannel() != chrome::VersionInfo::CHANNEL_BETA &&
2215       chrome::VersionInfo::GetChannel() != chrome::VersionInfo::CHANNEL_DEV) {
2216     return true;
2217   }
2218   // enable-data-reduction-proxy-alt is only available for the Dev channel.
2219   if (!strcmp("enable-data-reduction-proxy-alt", experiment.internal_name) &&
2220       chrome::VersionInfo::GetChannel() != chrome::VersionInfo::CHANNEL_DEV) {
2221     return true;
2222   }
2223 #endif
2224
2225   return false;
2226 }
2227
2228
2229 // Variant of GetSanitizedEnabledFlags that also removes any flags that aren't
2230 // enabled on the current platform.
2231 void GetSanitizedEnabledFlagsForCurrentPlatform(
2232     FlagsStorage* flags_storage, std::set<std::string>* result) {
2233   GetSanitizedEnabledFlags(flags_storage, result);
2234
2235   // Filter out any experiments that aren't enabled on the current platform.  We
2236   // don't remove these from prefs else syncing to a platform with a different
2237   // set of experiments would be lossy.
2238   std::set<std::string> platform_experiments;
2239   int current_platform = GetCurrentPlatform();
2240   for (size_t i = 0; i < num_experiments; ++i) {
2241     if (experiments[i].supported_platforms & current_platform)
2242       AddInternalName(experiments[i], &platform_experiments);
2243 #if defined(OS_CHROMEOS)
2244     if (experiments[i].supported_platforms & kOsCrOSOwnerOnly)
2245       AddInternalName(experiments[i], &platform_experiments);
2246 #endif
2247   }
2248
2249   std::set<std::string> new_enabled_experiments =
2250       base::STLSetIntersection<std::set<std::string> >(
2251           platform_experiments, *result);
2252
2253   result->swap(new_enabled_experiments);
2254 }
2255
2256 // Returns the Value representing the choice data in the specified experiment.
2257 base::Value* CreateChoiceData(
2258     const Experiment& experiment,
2259     const std::set<std::string>& enabled_experiments) {
2260   DCHECK(experiment.type == Experiment::MULTI_VALUE ||
2261          experiment.type == Experiment::ENABLE_DISABLE_VALUE);
2262   base::ListValue* result = new base::ListValue;
2263   for (int i = 0; i < experiment.num_choices; ++i) {
2264     base::DictionaryValue* value = new base::DictionaryValue;
2265     const std::string name = experiment.NameForChoice(i);
2266     value->SetString("internal_name", name);
2267     value->SetString("description", experiment.DescriptionForChoice(i));
2268     value->SetBoolean("selected", enabled_experiments.count(name) > 0);
2269     result->Append(value);
2270   }
2271   return result;
2272 }
2273
2274 }  // namespace
2275
2276 std::string Experiment::NameForChoice(int index) const {
2277   DCHECK(type == Experiment::MULTI_VALUE ||
2278          type == Experiment::ENABLE_DISABLE_VALUE);
2279   DCHECK_LT(index, num_choices);
2280   return std::string(internal_name) + testing::kMultiSeparator +
2281          base::IntToString(index);
2282 }
2283
2284 base::string16 Experiment::DescriptionForChoice(int index) const {
2285   DCHECK(type == Experiment::MULTI_VALUE ||
2286          type == Experiment::ENABLE_DISABLE_VALUE);
2287   DCHECK_LT(index, num_choices);
2288   int description_id;
2289   if (type == Experiment::ENABLE_DISABLE_VALUE) {
2290     const int kEnableDisableDescriptionIds[] = {
2291       IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
2292       IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
2293       IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
2294     };
2295     description_id = kEnableDisableDescriptionIds[index];
2296   } else {
2297     description_id = choices[index].description_id;
2298   }
2299   return l10n_util::GetStringUTF16(description_id);
2300 }
2301
2302 void ConvertFlagsToSwitches(FlagsStorage* flags_storage,
2303                             base::CommandLine* command_line,
2304                             SentinelsMode sentinels) {
2305   FlagsState::GetInstance()->ConvertFlagsToSwitches(flags_storage,
2306                                                     command_line,
2307                                                     sentinels);
2308 }
2309
2310 bool AreSwitchesIdenticalToCurrentCommandLine(
2311     const base::CommandLine& new_cmdline,
2312     const base::CommandLine& active_cmdline,
2313     std::set<base::CommandLine::StringType>* out_difference) {
2314   std::set<base::CommandLine::StringType> new_flags =
2315       ExtractFlagsFromCommandLine(new_cmdline);
2316   std::set<base::CommandLine::StringType> active_flags =
2317       ExtractFlagsFromCommandLine(active_cmdline);
2318
2319   bool result = false;
2320   // Needed because std::equal doesn't check if the 2nd set is empty.
2321   if (new_flags.size() == active_flags.size()) {
2322     result =
2323         std::equal(new_flags.begin(), new_flags.end(), active_flags.begin());
2324   }
2325
2326   if (out_difference && !result) {
2327     std::set_symmetric_difference(
2328         new_flags.begin(),
2329         new_flags.end(),
2330         active_flags.begin(),
2331         active_flags.end(),
2332         std::inserter(*out_difference, out_difference->begin()));
2333   }
2334
2335   return result;
2336 }
2337
2338 void GetFlagsExperimentsData(FlagsStorage* flags_storage,
2339                              FlagAccess access,
2340                              base::ListValue* supported_experiments,
2341                              base::ListValue* unsupported_experiments) {
2342   std::set<std::string> enabled_experiments;
2343   GetSanitizedEnabledFlags(flags_storage, &enabled_experiments);
2344
2345   int current_platform = GetCurrentPlatform();
2346
2347   for (size_t i = 0; i < num_experiments; ++i) {
2348     const Experiment& experiment = experiments[i];
2349     if (SkipConditionalExperiment(experiment, flags_storage))
2350       continue;
2351
2352     base::DictionaryValue* data = new base::DictionaryValue();
2353     data->SetString("internal_name", experiment.internal_name);
2354     data->SetString("name",
2355                     l10n_util::GetStringUTF16(experiment.visible_name_id));
2356     data->SetString("description",
2357                     l10n_util::GetStringUTF16(
2358                         experiment.visible_description_id));
2359
2360     base::ListValue* supported_platforms = new base::ListValue();
2361     AddOsStrings(experiment.supported_platforms, supported_platforms);
2362     data->Set("supported_platforms", supported_platforms);
2363
2364     switch (experiment.type) {
2365       case Experiment::SINGLE_VALUE:
2366         data->SetBoolean(
2367             "enabled",
2368             enabled_experiments.count(experiment.internal_name) > 0);
2369         break;
2370       case Experiment::MULTI_VALUE:
2371       case Experiment::ENABLE_DISABLE_VALUE:
2372         data->Set("choices", CreateChoiceData(experiment, enabled_experiments));
2373         break;
2374       default:
2375         NOTREACHED();
2376     }
2377
2378     bool supported = (experiment.supported_platforms & current_platform) != 0;
2379 #if defined(OS_CHROMEOS)
2380     if (access == kOwnerAccessToFlags &&
2381         (experiment.supported_platforms & kOsCrOSOwnerOnly) != 0) {
2382       supported = true;
2383     }
2384 #endif
2385     if (supported)
2386       supported_experiments->Append(data);
2387     else
2388       unsupported_experiments->Append(data);
2389   }
2390 }
2391
2392 bool IsRestartNeededToCommitChanges() {
2393   return FlagsState::GetInstance()->IsRestartNeededToCommitChanges();
2394 }
2395
2396 void SetExperimentEnabled(FlagsStorage* flags_storage,
2397                           const std::string& internal_name,
2398                           bool enable) {
2399   FlagsState::GetInstance()->SetExperimentEnabled(flags_storage,
2400                                                   internal_name, enable);
2401 }
2402
2403 void RemoveFlagsSwitches(
2404     std::map<std::string, base::CommandLine::StringType>* switch_list) {
2405   FlagsState::GetInstance()->RemoveFlagsSwitches(switch_list);
2406 }
2407
2408 void ResetAllFlags(FlagsStorage* flags_storage) {
2409   FlagsState::GetInstance()->ResetAllFlags(flags_storage);
2410 }
2411
2412 int GetCurrentPlatform() {
2413 #if defined(OS_MACOSX)
2414   return kOsMac;
2415 #elif defined(OS_WIN)
2416   return kOsWin;
2417 #elif defined(OS_CHROMEOS)  // Needs to be before the OS_LINUX check.
2418   return kOsCrOS;
2419 #elif defined(OS_LINUX) || defined(OS_OPENBSD)
2420   return kOsLinux;
2421 #elif defined(OS_ANDROID)
2422   return kOsAndroid;
2423 #else
2424 #error Unknown platform
2425 #endif
2426 }
2427
2428 void RecordUMAStatistics(FlagsStorage* flags_storage) {
2429   std::set<std::string> flags = flags_storage->GetFlags();
2430   for (const std::string& flag : flags) {
2431     std::string action("AboutFlags_");
2432     action += flag;
2433     content::RecordComputedAction(action);
2434   }
2435   // Since flag metrics are recorded every startup, add a tick so that the
2436   // stats can be made meaningful.
2437   if (flags.size())
2438     content::RecordAction(base::UserMetricsAction("AboutFlags_StartupTick"));
2439   content::RecordAction(base::UserMetricsAction("StartupTick"));
2440 }
2441
2442 base::HistogramBase::Sample GetSwitchUMAId(const std::string& switch_name) {
2443   return static_cast<base::HistogramBase::Sample>(
2444       metrics::HashMetricName(switch_name));
2445 }
2446
2447 void ReportCustomFlags(const std::string& uma_histogram_hame,
2448                        const std::set<std::string>& command_line_difference) {
2449   for (const std::string& flag : command_line_difference) {
2450     int uma_id = about_flags::testing::kBadSwitchFormatHistogramId;
2451     if (StartsWithASCII(flag, "--", true /* case_sensitive */)) {
2452       // Skip '--' before switch name.
2453       std::string switch_name(flag.substr(2));
2454
2455       // Kill value, if any.
2456       const size_t value_pos = switch_name.find('=');
2457       if (value_pos != std::string::npos)
2458         switch_name.resize(value_pos);
2459
2460       uma_id = GetSwitchUMAId(switch_name);
2461     } else {
2462       NOTREACHED() << "ReportCustomFlags(): flag '" << flag
2463                    << "' has incorrect format.";
2464     }
2465     DVLOG(1) << "ReportCustomFlags(): histogram='" << uma_histogram_hame
2466              << "' '" << flag << "', uma_id=" << uma_id;
2467
2468     // Sparse histogram macro does not cache the histogram, so it's safe
2469     // to use macro with non-static histogram name here.
2470     UMA_HISTOGRAM_SPARSE_SLOWLY(uma_histogram_hame, uma_id);
2471   }
2472 }
2473
2474 //////////////////////////////////////////////////////////////////////////////
2475 // FlagsState implementation.
2476
2477 namespace {
2478
2479 typedef std::map<std::string, std::pair<std::string, std::string> >
2480     NameToSwitchAndValueMap;
2481
2482 void SetFlagToSwitchMapping(const std::string& key,
2483                             const std::string& switch_name,
2484                             const std::string& switch_value,
2485                             NameToSwitchAndValueMap* name_to_switch_map) {
2486   DCHECK(name_to_switch_map->end() == name_to_switch_map->find(key));
2487   (*name_to_switch_map)[key] = std::make_pair(switch_name, switch_value);
2488 }
2489
2490 void FlagsState::ConvertFlagsToSwitches(FlagsStorage* flags_storage,
2491                                         base::CommandLine* command_line,
2492                                         SentinelsMode sentinels) {
2493   if (command_line->HasSwitch(switches::kNoExperiments))
2494     return;
2495
2496   std::set<std::string> enabled_experiments;
2497
2498   GetSanitizedEnabledFlagsForCurrentPlatform(flags_storage,
2499                                              &enabled_experiments);
2500
2501   NameToSwitchAndValueMap name_to_switch_map;
2502   for (size_t i = 0; i < num_experiments; ++i) {
2503     const Experiment& e = experiments[i];
2504     if (e.type == Experiment::SINGLE_VALUE) {
2505       SetFlagToSwitchMapping(e.internal_name, e.command_line_switch,
2506                              e.command_line_value, &name_to_switch_map);
2507     } else if (e.type == Experiment::MULTI_VALUE) {
2508       for (int j = 0; j < e.num_choices; ++j) {
2509         SetFlagToSwitchMapping(e.NameForChoice(j),
2510                                e.choices[j].command_line_switch,
2511                                e.choices[j].command_line_value,
2512                                &name_to_switch_map);
2513       }
2514     } else {
2515       DCHECK_EQ(e.type, Experiment::ENABLE_DISABLE_VALUE);
2516       SetFlagToSwitchMapping(e.NameForChoice(0), std::string(), std::string(),
2517                              &name_to_switch_map);
2518       SetFlagToSwitchMapping(e.NameForChoice(1), e.command_line_switch,
2519                              e.command_line_value, &name_to_switch_map);
2520       SetFlagToSwitchMapping(e.NameForChoice(2), e.disable_command_line_switch,
2521                              e.disable_command_line_value, &name_to_switch_map);
2522     }
2523   }
2524
2525   if (sentinels == kAddSentinels) {
2526     command_line->AppendSwitch(switches::kFlagSwitchesBegin);
2527     flags_switches_.insert(
2528         std::pair<std::string, std::string>(switches::kFlagSwitchesBegin,
2529                                             std::string()));
2530   }
2531   for (const std::string& experiment_name : enabled_experiments) {
2532     NameToSwitchAndValueMap::const_iterator name_to_switch_it =
2533         name_to_switch_map.find(experiment_name);
2534     if (name_to_switch_it == name_to_switch_map.end()) {
2535       NOTREACHED();
2536       continue;
2537     }
2538
2539 #if defined(OS_CHROMEOS)
2540     // On Chrome OS setting command line flag may make browser to restart on
2541     // user login. As this flag eventually will be set to a significant number
2542     // of users skip manual-enhanced-bookmarks to avoid restart.
2543     if (experiment_name == "manual-enhanced-bookmarks")
2544       continue;
2545 #endif
2546
2547     const std::pair<std::string, std::string>&
2548         switch_and_value_pair = name_to_switch_it->second;
2549
2550     CHECK(!switch_and_value_pair.first.empty());
2551     command_line->AppendSwitchASCII(switch_and_value_pair.first,
2552                                     switch_and_value_pair.second);
2553     flags_switches_[switch_and_value_pair.first] = switch_and_value_pair.second;
2554   }
2555   if (sentinels == kAddSentinels) {
2556     command_line->AppendSwitch(switches::kFlagSwitchesEnd);
2557     flags_switches_.insert(
2558         std::pair<std::string, std::string>(switches::kFlagSwitchesEnd,
2559                                             std::string()));
2560   }
2561 }
2562
2563 bool FlagsState::IsRestartNeededToCommitChanges() {
2564   return needs_restart_;
2565 }
2566
2567 void FlagsState::SetExperimentEnabled(FlagsStorage* flags_storage,
2568                                       const std::string& internal_name,
2569                                       bool enable) {
2570   size_t at_index = internal_name.find(testing::kMultiSeparator);
2571   if (at_index != std::string::npos) {
2572     DCHECK(enable);
2573     // We're being asked to enable a multi-choice experiment. Disable the
2574     // currently selected choice.
2575     DCHECK_NE(at_index, 0u);
2576     const std::string experiment_name = internal_name.substr(0, at_index);
2577     SetExperimentEnabled(flags_storage, experiment_name, false);
2578
2579     // And enable the new choice, if it is not the default first choice.
2580     if (internal_name != experiment_name + "@0") {
2581       std::set<std::string> enabled_experiments;
2582       GetSanitizedEnabledFlags(flags_storage, &enabled_experiments);
2583       needs_restart_ |= enabled_experiments.insert(internal_name).second;
2584       flags_storage->SetFlags(enabled_experiments);
2585     }
2586     return;
2587   }
2588
2589   std::set<std::string> enabled_experiments;
2590   GetSanitizedEnabledFlags(flags_storage, &enabled_experiments);
2591
2592   const Experiment* e = NULL;
2593   for (size_t i = 0; i < num_experiments; ++i) {
2594     if (experiments[i].internal_name == internal_name) {
2595       e = experiments + i;
2596       break;
2597     }
2598   }
2599   DCHECK(e);
2600
2601   if (e->type == Experiment::SINGLE_VALUE) {
2602     if (enable)
2603       needs_restart_ |= enabled_experiments.insert(internal_name).second;
2604     else
2605       needs_restart_ |= (enabled_experiments.erase(internal_name) > 0);
2606   } else {
2607     if (enable) {
2608       // Enable the first choice.
2609       needs_restart_ |= enabled_experiments.insert(e->NameForChoice(0)).second;
2610     } else {
2611       // Find the currently enabled choice and disable it.
2612       for (int i = 0; i < e->num_choices; ++i) {
2613         std::string choice_name = e->NameForChoice(i);
2614         if (enabled_experiments.find(choice_name) !=
2615             enabled_experiments.end()) {
2616           needs_restart_ = true;
2617           enabled_experiments.erase(choice_name);
2618           // Continue on just in case there's a bug and more than one
2619           // experiment for this choice was enabled.
2620         }
2621       }
2622     }
2623   }
2624
2625   flags_storage->SetFlags(enabled_experiments);
2626 }
2627
2628 void FlagsState::RemoveFlagsSwitches(
2629     std::map<std::string, base::CommandLine::StringType>* switch_list) {
2630   for (const auto& entry : flags_switches_)
2631     switch_list->erase(entry.first);
2632 }
2633
2634 void FlagsState::ResetAllFlags(FlagsStorage* flags_storage) {
2635   needs_restart_ = true;
2636
2637   std::set<std::string> no_experiments;
2638   flags_storage->SetFlags(no_experiments);
2639 }
2640
2641 void FlagsState::reset() {
2642   needs_restart_ = false;
2643   flags_switches_.clear();
2644 }
2645
2646 }  // namespace
2647
2648 namespace testing {
2649
2650 // WARNING: '@' is also used in the html file. If you update this constant you
2651 // also need to update the html file.
2652 const char kMultiSeparator[] = "@";
2653
2654 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
2655
2656 void ClearState() {
2657   FlagsState::GetInstance()->reset();
2658 }
2659
2660 void SetExperiments(const Experiment* e, size_t count) {
2661   if (!e) {
2662     experiments = kExperiments;
2663     num_experiments = arraysize(kExperiments);
2664   } else {
2665     experiments = e;
2666     num_experiments = count;
2667   }
2668 }
2669
2670 const Experiment* GetExperiments(size_t* count) {
2671   *count = num_experiments;
2672   return experiments;
2673 }
2674
2675 }  // namespace testing
2676
2677 }  // namespace about_flags