chrome/browser/extensions/extension_webkit_preferences.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/extensions/extension_webkit_preferences.h"
   6
   7 #include "base/command_line.h"
   8 #include "chrome/common/chrome_switches.h"
   9 #include "chrome/common/extensions/extension.h"
  10 #include "extensions/common/manifest.h"
  11 #include "webkit/common/webpreferences.h"
  12
  13 namespace extension_webkit_preferences {
  14
  15 void SetPreferences(const extensions::Extension* extension,
  16                     extensions::ViewType render_view_type,
  17                     WebPreferences* webkit_prefs) {
  18   if (!extension)
  19     return;
  20
  21   if (!extension->is_hosted_app()) {
  22     // Extensions are trusted so we override any user preferences for disabling
  23     // javascript or images.
  24     webkit_prefs->loads_images_automatically = true;
  25     webkit_prefs->javascript_enabled = true;
  26
  27     // Tabs aren't typically allowed to close windows. But extensions shouldn't
  28     // be subject to that.
  29     webkit_prefs->allow_scripts_to_close_windows = true;
  30
  31     // Disable gpu acceleration for extension background pages to avoid
  32     // unecessarily creating a compositor context for them.
  33     if (render_view_type == extensions::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
  34       webkit_prefs->accelerated_compositing_enabled = false;
  35       webkit_prefs->force_compositing_mode = false;
  36     }
  37   }
  38
  39   if (extension->is_platform_app()) {
  40     webkit_prefs->databases_enabled = false;
  41     webkit_prefs->local_storage_enabled = false;
  42     webkit_prefs->sync_xhr_in_documents_enabled = false;
  43     webkit_prefs->cookie_enabled = false;
  44   }
  45
  46   // Enable WebGL features that regular pages can't access, since they add
  47   // more risk of fingerprinting.
  48   webkit_prefs->privileged_webgl_extensions_enabled = true;
  49
  50   // If this is a component extension, then apply the same poliy for
  51   // accelerated compositing as for chrome: URLs (from
  52   // WebContents::GetWebkitPrefs).  This is important for component extensions
  53   // like the file manager which are sometimes loaded using chrome: URLs and
  54   // sometimes loaded with chrome-extension: URLs - we should expect the
  55   // performance characteristics to be similar in both cases.
  56   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
  57   if (extension->location() == extensions::Manifest::COMPONENT &&
  58       !command_line.HasSwitch(switches::kAllowWebUICompositing)) {
  59     webkit_prefs->accelerated_compositing_enabled = false;
  60     webkit_prefs->accelerated_2d_canvas_enabled = false;
  61   }
  62 }
  63
  64 }  // namespace extension_webkit_preferences