cc/trees/layer_tree_impl.cc

   1 // Copyright 2011 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 "cc/trees/layer_tree_impl.h"
   6
   7 #include <algorithm>
   8 #include <limits>
   9 #include <set>
  10
  11 #include "base/trace_event/trace_event.h"
  12 #include "base/trace_event/trace_event_argument.h"
  13 #include "cc/animation/keyframed_animation_curve.h"
  14 #include "cc/animation/scrollbar_animation_controller.h"
  15 #include "cc/animation/scrollbar_animation_controller_linear_fade.h"
  16 #include "cc/animation/scrollbar_animation_controller_thinning.h"
  17 #include "cc/base/math_util.h"
  18 #include "cc/base/synced_property.h"
  19 #include "cc/debug/devtools_instrumentation.h"
  20 #include "cc/debug/traced_value.h"
  21 #include "cc/input/layer_scroll_offset_delegate.h"
  22 #include "cc/input/page_scale_animation.h"
  23 #include "cc/layers/heads_up_display_layer_impl.h"
  24 #include "cc/layers/layer.h"
  25 #include "cc/layers/layer_iterator.h"
  26 #include "cc/layers/render_surface_impl.h"
  27 #include "cc/layers/scrollbar_layer_impl_base.h"
  28 #include "cc/resources/ui_resource_request.h"
  29 #include "cc/trees/layer_tree_host_common.h"
  30 #include "cc/trees/layer_tree_host_impl.h"
  31 #include "cc/trees/occlusion_tracker.h"
  32 #include "cc/trees/property_tree_builder.h"
  33 #include "ui/gfx/geometry/point_conversions.h"
  34 #include "ui/gfx/geometry/size_conversions.h"
  35 #include "ui/gfx/geometry/vector2d_conversions.h"
  36
  37 namespace cc {
  38
  39 LayerTreeImpl::LayerTreeImpl(
  40     LayerTreeHostImpl* layer_tree_host_impl,
  41     scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor,
  42     scoped_refptr<SyncedTopControls> top_controls_shown_ratio,
  43     scoped_refptr<SyncedElasticOverscroll> elastic_overscroll)
  44     : layer_tree_host_impl_(layer_tree_host_impl),
  45       source_frame_number_(-1),
  46       hud_layer_(0),
  47       currently_scrolling_layer_(NULL),
  48       root_layer_scroll_offset_delegate_(NULL),
  49       background_color_(0),
  50       has_transparent_background_(false),
  51       overscroll_elasticity_layer_(NULL),
  52       page_scale_layer_(NULL),
  53       inner_viewport_scroll_layer_(NULL),
  54       outer_viewport_scroll_layer_(NULL),
  55       page_scale_factor_(page_scale_factor),
  56       min_page_scale_factor_(0),
  57       max_page_scale_factor_(0),
  58       elastic_overscroll_(elastic_overscroll),
  59       scrolling_layer_id_from_previous_tree_(0),
  60       contents_textures_purged_(false),
  61       viewport_size_invalid_(false),
  62       needs_update_draw_properties_(true),
  63       needs_full_tree_sync_(true),
  64       next_activation_forces_redraw_(false),
  65       has_ever_been_drawn_(false),
  66       render_surface_layer_list_id_(0),
  67       top_controls_shrink_blink_size_(false),
  68       top_controls_height_(0),
  69       top_controls_shown_ratio_(top_controls_shown_ratio) {
  70 }
  71
  72 LayerTreeImpl::~LayerTreeImpl() {
  73   BreakSwapPromises(IsActiveTree() ? SwapPromise::SWAP_FAILS
  74                                    : SwapPromise::ACTIVATION_FAILS);
  75
  76   // Need to explicitly clear the tree prior to destroying this so that
  77   // the LayerTreeImpl pointer is still valid in the LayerImpl dtor.
  78   DCHECK(!root_layer_);
  79   DCHECK(layers_with_copy_output_request_.empty());
  80 }
  81
  82 void LayerTreeImpl::Shutdown() {
  83   root_layer_ = nullptr;
  84 }
  85
  86 void LayerTreeImpl::ReleaseResources() {
  87   if (root_layer_) {
  88     LayerTreeHostCommon::CallFunctionForSubtree(
  89         root_layer_.get(), [](LayerImpl* layer) { layer->ReleaseResources(); });
  90   }
  91 }
  92
  93 void LayerTreeImpl::RecreateResources() {
  94   if (root_layer_) {
  95     LayerTreeHostCommon::CallFunctionForSubtree(
  96         root_layer_.get(),
  97         [](LayerImpl* layer) { layer->RecreateResources(); });
  98   }
  99 }
 100
 101 void LayerTreeImpl::GatherFrameTimingRequestIds(
 102     std::vector<int64_t>* request_ids) {
 103   if (!root_layer_)
 104     return;
 105
 106   // TODO(vmpstr): Early out if there are no requests on any of the layers. For
 107   // that, we need to inform LayerTreeImpl whenever there are requests when we
 108   // get them.
 109   LayerTreeHostCommon::CallFunctionForSubtree(
 110       root_layer_.get(), [request_ids](LayerImpl* layer) {
 111         layer->GatherFrameTimingRequestIds(request_ids);
 112       });
 113 }
 114
 115 bool LayerTreeImpl::IsExternalScrollActive() const {
 116   return root_layer_scroll_offset_delegate_ &&
 117          root_layer_scroll_offset_delegate_->IsExternalScrollActive();
 118 }
 119
 120 void LayerTreeImpl::DidUpdateScrollOffset(int layer_id) {
 121   int inner_layer_id = InnerViewportScrollLayer()
 122                            ? InnerViewportScrollLayer()->id()
 123                            : Layer::INVALID_ID;
 124   int outer_layer_id = OuterViewportScrollLayer()
 125                            ? OuterViewportScrollLayer()->id()
 126                            : Layer::INVALID_ID;
 127   if (layer_id != outer_layer_id && layer_id != inner_layer_id)
 128     return;
 129
 130   if (!root_layer_scroll_offset_delegate_)
 131     return;
 132
 133   UpdateRootScrollOffsetDelegate();
 134 }
 135
 136 void LayerTreeImpl::SetRootLayer(scoped_ptr<LayerImpl> layer) {
 137   root_layer_ = layer.Pass();
 138   currently_scrolling_layer_ = NULL;
 139   inner_viewport_scroll_layer_ = NULL;
 140   outer_viewport_scroll_layer_ = NULL;
 141   page_scale_layer_ = NULL;
 142
 143   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 144 }
 145
 146 LayerImpl* LayerTreeImpl::InnerViewportScrollLayer() const {
 147   return inner_viewport_scroll_layer_;
 148 }
 149
 150 LayerImpl* LayerTreeImpl::OuterViewportScrollLayer() const {
 151   return outer_viewport_scroll_layer_;
 152 }
 153
 154 gfx::ScrollOffset LayerTreeImpl::TotalScrollOffset() const {
 155   gfx::ScrollOffset offset;
 156
 157   if (inner_viewport_scroll_layer_)
 158     offset += inner_viewport_scroll_layer_->CurrentScrollOffset();
 159
 160   if (outer_viewport_scroll_layer_)
 161     offset += outer_viewport_scroll_layer_->CurrentScrollOffset();
 162
 163   return offset;
 164 }
 165
 166 gfx::ScrollOffset LayerTreeImpl::TotalMaxScrollOffset() const {
 167   gfx::ScrollOffset offset;
 168
 169   if (inner_viewport_scroll_layer_)
 170     offset += inner_viewport_scroll_layer_->MaxScrollOffset();
 171
 172   if (outer_viewport_scroll_layer_)
 173     offset += outer_viewport_scroll_layer_->MaxScrollOffset();
 174
 175   return offset;
 176 }
 177
 178 scoped_ptr<LayerImpl> LayerTreeImpl::DetachLayerTree() {
 179   // Clear all data structures that have direct references to the layer tree.
 180   scrolling_layer_id_from_previous_tree_ =
 181     currently_scrolling_layer_ ? currently_scrolling_layer_->id() : 0;
 182   inner_viewport_scroll_layer_ = NULL;
 183   outer_viewport_scroll_layer_ = NULL;
 184   page_scale_layer_ = NULL;
 185   currently_scrolling_layer_ = NULL;
 186
 187   render_surface_layer_list_.clear();
 188   set_needs_update_draw_properties();
 189   return root_layer_.Pass();
 190 }
 191
 192 void LayerTreeImpl::PushPropertiesTo(LayerTreeImpl* target_tree) {
 193   // The request queue should have been processed and does not require a push.
 194   DCHECK_EQ(ui_resource_request_queue_.size(), 0u);
 195
 196   target_tree->SetPropertyTrees(property_trees_);
 197
 198   if (next_activation_forces_redraw_) {
 199     target_tree->ForceRedrawNextActivation();
 200     next_activation_forces_redraw_ = false;
 201   }
 202
 203   target_tree->PassSwapPromises(&swap_promise_list_);
 204
 205   target_tree->set_top_controls_shrink_blink_size(
 206       top_controls_shrink_blink_size_);
 207   target_tree->set_top_controls_height(top_controls_height_);
 208   target_tree->PushTopControls(nullptr);
 209
 210   // Active tree already shares the page_scale_factor object with pending
 211   // tree so only the limits need to be provided.
 212   target_tree->PushPageScaleFactorAndLimits(nullptr, min_page_scale_factor(),
 213                                             max_page_scale_factor());
 214   target_tree->elastic_overscroll()->PushPendingToActive();
 215
 216   target_tree->pending_page_scale_animation_ =
 217       pending_page_scale_animation_.Pass();
 218
 219   if (page_scale_layer_ && inner_viewport_scroll_layer_) {
 220     target_tree->SetViewportLayersFromIds(
 221         overscroll_elasticity_layer_ ? overscroll_elasticity_layer_->id()
 222                                      : Layer::INVALID_ID,
 223         page_scale_layer_->id(), inner_viewport_scroll_layer_->id(),
 224         outer_viewport_scroll_layer_ ? outer_viewport_scroll_layer_->id()
 225                                      : Layer::INVALID_ID);
 226   } else {
 227     target_tree->ClearViewportLayers();
 228   }
 229
 230   target_tree->RegisterSelection(selection_);
 231
 232   // This should match the property synchronization in
 233   // LayerTreeHost::finishCommitOnImplThread().
 234   target_tree->set_source_frame_number(source_frame_number());
 235   target_tree->set_background_color(background_color());
 236   target_tree->set_has_transparent_background(has_transparent_background());
 237
 238   if (ContentsTexturesPurged())
 239     target_tree->SetContentsTexturesPurged();
 240   else
 241     target_tree->ResetContentsTexturesPurged();
 242
 243   if (ViewportSizeInvalid())
 244     target_tree->SetViewportSizeInvalid();
 245   else
 246     target_tree->ResetViewportSizeInvalid();
 247
 248   if (hud_layer())
 249     target_tree->set_hud_layer(static_cast<HeadsUpDisplayLayerImpl*>(
 250         LayerTreeHostCommon::FindLayerInSubtree(
 251             target_tree->root_layer(), hud_layer()->id())));
 252   else
 253     target_tree->set_hud_layer(NULL);
 254
 255   target_tree->has_ever_been_drawn_ = false;
 256 }
 257
 258 LayerImpl* LayerTreeImpl::InnerViewportContainerLayer() const {
 259   return inner_viewport_scroll_layer_
 260              ? inner_viewport_scroll_layer_->scroll_clip_layer()
 261              : NULL;
 262 }
 263
 264 LayerImpl* LayerTreeImpl::OuterViewportContainerLayer() const {
 265   return outer_viewport_scroll_layer_
 266              ? outer_viewport_scroll_layer_->scroll_clip_layer()
 267              : NULL;
 268 }
 269
 270 LayerImpl* LayerTreeImpl::CurrentlyScrollingLayer() const {
 271   DCHECK(IsActiveTree());
 272   return currently_scrolling_layer_;
 273 }
 274
 275 void LayerTreeImpl::SetCurrentlyScrollingLayer(LayerImpl* layer) {
 276   if (currently_scrolling_layer_ == layer)
 277     return;
 278
 279   if (currently_scrolling_layer_ &&
 280       currently_scrolling_layer_->scrollbar_animation_controller())
 281     currently_scrolling_layer_->scrollbar_animation_controller()
 282         ->DidScrollEnd();
 283   currently_scrolling_layer_ = layer;
 284   if (layer && layer->scrollbar_animation_controller())
 285     layer->scrollbar_animation_controller()->DidScrollBegin();
 286 }
 287
 288 void LayerTreeImpl::ClearCurrentlyScrollingLayer() {
 289   SetCurrentlyScrollingLayer(NULL);
 290   scrolling_layer_id_from_previous_tree_ = 0;
 291 }
 292
 293 namespace {
 294
 295 void ForceScrollbarParameterUpdateAfterScaleChange(LayerImpl* current_layer) {
 296   if (!current_layer)
 297     return;
 298
 299   while (current_layer) {
 300     current_layer->ScrollbarParametersDidChange(false);
 301     current_layer = current_layer->parent();
 302   }
 303 }
 304
 305 }  // namespace
 306
 307 float LayerTreeImpl::ClampPageScaleFactorToLimits(
 308     float page_scale_factor) const {
 309   if (min_page_scale_factor_ && page_scale_factor < min_page_scale_factor_)
 310     page_scale_factor = min_page_scale_factor_;
 311   else if (max_page_scale_factor_ && page_scale_factor > max_page_scale_factor_)
 312     page_scale_factor = max_page_scale_factor_;
 313   return page_scale_factor;
 314 }
 315
 316 void LayerTreeImpl::UpdatePropertyTreeScrollingFromMainThread() {
 317   // TODO(enne): This should get replaced by pulling out scrolling into its own
 318   // tree.  Then scrolls would have their own way of synchronizing across
 319   // commits.  This occurs to push updates from scrolling deltas on the
 320   // compositor thread that have occurred after begin frame to a newly-committed
 321   // property tree.
 322   if (!root_layer())
 323     return;
 324   LayerTreeHostCommon::CallFunctionForSubtree(
 325       root_layer(), [](LayerImpl* layer) {
 326         layer->UpdatePropertyTreeForScrollingIfNeeded();
 327       });
 328 }
 329
 330 void LayerTreeImpl::SetPageScaleOnActiveTree(float active_page_scale) {
 331   DCHECK(IsActiveTree());
 332   if (page_scale_factor()->SetCurrent(
 333           ClampPageScaleFactorToLimits(active_page_scale)))
 334     DidUpdatePageScale();
 335 }
 336
 337 void LayerTreeImpl::PushPageScaleFromMainThread(float page_scale_factor,
 338                                                 float min_page_scale_factor,
 339                                                 float max_page_scale_factor) {
 340   PushPageScaleFactorAndLimits(&page_scale_factor, min_page_scale_factor,
 341                                max_page_scale_factor);
 342 }
 343
 344 void LayerTreeImpl::PushPageScaleFactorAndLimits(const float* page_scale_factor,
 345                                                  float min_page_scale_factor,
 346                                                  float max_page_scale_factor) {
 347   DCHECK(page_scale_factor || IsActiveTree());
 348   bool changed_page_scale = false;
 349   if (page_scale_factor) {
 350     DCHECK(!IsActiveTree() || !layer_tree_host_impl_->pending_tree());
 351     changed_page_scale |= page_scale_factor_->Delta() != 1.f;
 352     // TODO(enne): Once CDP goes away, ignore this call below.  The only time
 353     // the property trees will differ is if there's been a page scale on the
 354     // compositor thread after the begin frame, which is the delta check above.
 355     changed_page_scale |=
 356         page_scale_factor_->PushFromMainThread(*page_scale_factor);
 357   }
 358   if (IsActiveTree()) {
 359     // TODO(enne): Pushing from pending to active should never require
 360     // DidUpdatePageScale.  The values should already be set by the fully
 361     // computed property trees being synced from one tree to another.  Remove
 362     // this once CDP goes away.
 363     changed_page_scale |= page_scale_factor_->PushPendingToActive();
 364   }
 365
 366   changed_page_scale |=
 367       SetPageScaleFactorLimits(min_page_scale_factor, max_page_scale_factor);
 368
 369   if (changed_page_scale)
 370     DidUpdatePageScale();
 371 }
 372
 373 void LayerTreeImpl::set_top_controls_shrink_blink_size(bool shrink) {
 374   if (top_controls_shrink_blink_size_ == shrink)
 375     return;
 376
 377   top_controls_shrink_blink_size_ = shrink;
 378   if (IsActiveTree())
 379     layer_tree_host_impl_->UpdateViewportContainerSizes();
 380 }
 381
 382 void LayerTreeImpl::set_top_controls_height(float top_controls_height) {
 383   if (top_controls_height_ == top_controls_height)
 384     return;
 385
 386   top_controls_height_ = top_controls_height;
 387   if (IsActiveTree())
 388     layer_tree_host_impl_->UpdateViewportContainerSizes();
 389 }
 390
 391 bool LayerTreeImpl::SetCurrentTopControlsShownRatio(float ratio) {
 392   ratio = std::max(ratio, 0.f);
 393   ratio = std::min(ratio, 1.f);
 394   return top_controls_shown_ratio_->SetCurrent(ratio);
 395 }
 396
 397 void LayerTreeImpl::PushTopControlsFromMainThread(
 398     float top_controls_shown_ratio) {
 399   PushTopControls(&top_controls_shown_ratio);
 400 }
 401
 402 void LayerTreeImpl::PushTopControls(const float* top_controls_shown_ratio) {
 403   DCHECK(top_controls_shown_ratio || IsActiveTree());
 404
 405   if (top_controls_shown_ratio) {
 406     DCHECK(!IsActiveTree() || !layer_tree_host_impl_->pending_tree());
 407     top_controls_shown_ratio_->PushFromMainThread(*top_controls_shown_ratio);
 408   }
 409   if (IsActiveTree()) {
 410     if (top_controls_shown_ratio_->PushPendingToActive())
 411       layer_tree_host_impl_->DidChangeTopControlsPosition();
 412   }
 413 }
 414
 415 bool LayerTreeImpl::SetPageScaleFactorLimits(float min_page_scale_factor,
 416                                              float max_page_scale_factor) {
 417   if (min_page_scale_factor == min_page_scale_factor_ &&
 418       max_page_scale_factor == max_page_scale_factor_)
 419     return false;
 420
 421   min_page_scale_factor_ = min_page_scale_factor;
 422   max_page_scale_factor_ = max_page_scale_factor;
 423
 424   return true;
 425 }
 426
 427 void LayerTreeImpl::DidUpdatePageScale() {
 428   if (IsActiveTree())
 429     page_scale_factor()->SetCurrent(
 430         ClampPageScaleFactorToLimits(current_page_scale_factor()));
 431
 432   set_needs_update_draw_properties();
 433
 434   if (root_layer_scroll_offset_delegate_) {
 435     root_layer_scroll_offset_delegate_->UpdateRootLayerState(
 436         TotalScrollOffset(), TotalMaxScrollOffset(), ScrollableSize(),
 437         current_page_scale_factor(), min_page_scale_factor_,
 438         max_page_scale_factor_);
 439   }
 440
 441   if (page_scale_layer() && page_scale_layer()->transform_tree_index() != -1) {
 442     TransformNode* node = property_trees_.transform_tree.Node(
 443         page_scale_layer()->transform_tree_index());
 444     node->data.post_local_scale_factor = current_page_scale_factor();
 445     node->data.needs_local_transform_update = true;
 446     // TODO(enne): property trees can't ask the layer these things, but
 447     // the page scale layer should *just* be the page scale.
 448     DCHECK_EQ(page_scale_layer()->position().ToString(),
 449               gfx::PointF().ToString());
 450     DCHECK_EQ(page_scale_layer()->transform_origin().ToString(),
 451               gfx::Point3F().ToString());
 452     node->data.update_post_local_transform(gfx::PointF(), gfx::Point3F());
 453     property_trees_.transform_tree.set_needs_update(true);
 454   }
 455
 456   ForceScrollbarParameterUpdateAfterScaleChange(page_scale_layer());
 457
 458   HideInnerViewportScrollbarsIfNearMinimumScale();
 459 }
 460
 461 void LayerTreeImpl::HideInnerViewportScrollbarsIfNearMinimumScale() {
 462   if (!InnerViewportContainerLayer())
 463     return;
 464
 465   LayerImpl::ScrollbarSet* scrollbars =
 466       InnerViewportContainerLayer()->scrollbars();
 467
 468   if (!scrollbars)
 469     return;
 470
 471   for (LayerImpl::ScrollbarSet::iterator it = scrollbars->begin();
 472        it != scrollbars->end();
 473        ++it) {
 474     ScrollbarLayerImplBase* scrollbar = *it;
 475     float minimum_scale_to_show_at =
 476         min_page_scale_factor() * settings().scrollbar_show_scale_threshold;
 477     scrollbar->SetHideLayerAndSubtree(
 478         current_page_scale_factor() < minimum_scale_to_show_at);
 479   }
 480 }
 481
 482 SyncedProperty<ScaleGroup>* LayerTreeImpl::page_scale_factor() {
 483   return page_scale_factor_.get();
 484 }
 485
 486 const SyncedProperty<ScaleGroup>* LayerTreeImpl::page_scale_factor() const {
 487   return page_scale_factor_.get();
 488 }
 489
 490 gfx::SizeF LayerTreeImpl::ScrollableViewportSize() const {
 491   if (!InnerViewportContainerLayer())
 492     return gfx::SizeF();
 493
 494   return gfx::ScaleSize(InnerViewportContainerLayer()->BoundsForScrolling(),
 495                         1.0f / current_page_scale_factor());
 496 }
 497
 498 gfx::Rect LayerTreeImpl::RootScrollLayerDeviceViewportBounds() const {
 499   LayerImpl* root_scroll_layer = OuterViewportScrollLayer()
 500                                      ? OuterViewportScrollLayer()
 501                                      : InnerViewportScrollLayer();
 502   if (!root_scroll_layer || root_scroll_layer->children().empty())
 503     return gfx::Rect();
 504   LayerImpl* layer = root_scroll_layer->children()[0];
 505   return MathUtil::MapEnclosingClippedRect(layer->screen_space_transform(),
 506                                            gfx::Rect(layer->bounds()));
 507 }
 508
 509 void LayerTreeImpl::ApplySentScrollAndScaleDeltasFromAbortedCommit() {
 510   DCHECK(IsActiveTree());
 511
 512   page_scale_factor()->AbortCommit();
 513   top_controls_shown_ratio()->AbortCommit();
 514   elastic_overscroll()->AbortCommit();
 515
 516   if (!root_layer())
 517     return;
 518
 519   LayerTreeHostCommon::CallFunctionForSubtree(
 520       root_layer(), [](LayerImpl* layer) {
 521         layer->ApplySentScrollDeltasFromAbortedCommit();
 522       });
 523 }
 524
 525 void LayerTreeImpl::SetViewportLayersFromIds(
 526     int overscroll_elasticity_layer_id,
 527     int page_scale_layer_id,
 528     int inner_viewport_scroll_layer_id,
 529     int outer_viewport_scroll_layer_id) {
 530   overscroll_elasticity_layer_ = LayerById(overscroll_elasticity_layer_id);
 531   page_scale_layer_ = LayerById(page_scale_layer_id);
 532   DCHECK(page_scale_layer_);
 533
 534   inner_viewport_scroll_layer_ =
 535       LayerById(inner_viewport_scroll_layer_id);
 536   DCHECK(inner_viewport_scroll_layer_);
 537
 538   outer_viewport_scroll_layer_ =
 539       LayerById(outer_viewport_scroll_layer_id);
 540   DCHECK(outer_viewport_scroll_layer_ ||
 541          outer_viewport_scroll_layer_id == Layer::INVALID_ID);
 542
 543   HideInnerViewportScrollbarsIfNearMinimumScale();
 544 }
 545
 546 void LayerTreeImpl::ClearViewportLayers() {
 547   page_scale_layer_ = NULL;
 548   inner_viewport_scroll_layer_ = NULL;
 549   outer_viewport_scroll_layer_ = NULL;
 550 }
 551
 552 bool LayerTreeImpl::UpdateDrawProperties(bool update_lcd_text) {
 553   if (!needs_update_draw_properties_)
 554     return true;
 555
 556   // Calling UpdateDrawProperties must clear this flag, so there can be no
 557   // early outs before this.
 558   needs_update_draw_properties_ = false;
 559
 560   // For max_texture_size.  When the renderer is re-created in
 561   // CreateAndSetRenderer, the needs update draw properties flag is set
 562   // again.
 563   if (!layer_tree_host_impl_->renderer())
 564     return false;
 565
 566   // Clear this after the renderer early out, as it should still be
 567   // possible to hit test even without a renderer.
 568   render_surface_layer_list_.clear();
 569
 570   if (!root_layer())
 571     return false;
 572
 573   {
 574     TRACE_EVENT2(
 575         "cc", "LayerTreeImpl::UpdateDrawProperties::CalculateDrawProperties",
 576         "IsActive", IsActiveTree(), "SourceFrameNumber", source_frame_number_);
 577     LayerImpl* page_scale_layer =
 578         page_scale_layer_ ? page_scale_layer_ : InnerViewportContainerLayer();
 579     bool can_render_to_separate_surface =
 580         (layer_tree_host_impl_->GetDrawMode() !=
 581          DRAW_MODE_RESOURCELESS_SOFTWARE);
 582
 583     ++render_surface_layer_list_id_;
 584
 585     LayerTreeHostCommon::CalcDrawPropsImplInputs inputs(
 586         root_layer(), DrawViewportSize(),
 587         layer_tree_host_impl_->DrawTransform(), device_scale_factor(),
 588         current_page_scale_factor(), page_scale_layer,
 589         elastic_overscroll()->Current(IsActiveTree()),
 590         overscroll_elasticity_layer_, resource_provider()->max_texture_size(),
 591         settings().can_use_lcd_text, settings().layers_always_allowed_lcd_text,
 592         can_render_to_separate_surface,
 593         settings().layer_transforms_should_scale_layer_contents,
 594         settings().verify_property_trees, &render_surface_layer_list_,
 595         render_surface_layer_list_id_, &property_trees_);
 596     LayerTreeHostCommon::CalculateDrawProperties(&inputs);
 597   }
 598
 599   {
 600     TRACE_EVENT2("cc", "LayerTreeImpl::UpdateDrawProperties::Occlusion",
 601                  "IsActive", IsActiveTree(), "SourceFrameNumber",
 602                  source_frame_number_);
 603     OcclusionTracker occlusion_tracker(
 604         root_layer()->render_surface()->content_rect());
 605     occlusion_tracker.set_minimum_tracking_size(
 606         settings().minimum_occlusion_tracking_size);
 607
 608     // LayerIterator is used here instead of CallFunctionForSubtree to only
 609     // UpdateTilePriorities on layers that will be visible (and thus have valid
 610     // draw properties) and not because any ordering is required.
 611     auto end = LayerIterator<LayerImpl>::End(&render_surface_layer_list_);
 612     for (auto it = LayerIterator<LayerImpl>::Begin(&render_surface_layer_list_);
 613          it != end; ++it) {
 614       occlusion_tracker.EnterLayer(it);
 615
 616       // There are very few render targets so this should be cheap to do for
 617       // each layer instead of something more complicated.
 618       bool inside_replica = false;
 619       LayerImpl* layer = it->render_target();
 620       while (layer && !inside_replica) {
 621         if (layer->render_target()->has_replica())
 622           inside_replica = true;
 623         layer = layer->render_target()->parent();
 624       }
 625
 626       // Don't use occlusion if a layer will appear in a replica, since the
 627       // tile raster code does not know how to look for the replica and would
 628       // consider it occluded even though the replica is visible.
 629       // Since occlusion is only used for browser compositor (i.e.
 630       // use_occlusion_for_tile_prioritization) and it won't use replicas,
 631       // this should matter not.
 632
 633       if (it.represents_itself()) {
 634         Occlusion occlusion =
 635             inside_replica ? Occlusion()
 636                            : occlusion_tracker.GetCurrentOcclusionForLayer(
 637                                  it->draw_transform());
 638         it->draw_properties().occlusion_in_content_space = occlusion;
 639       }
 640
 641       if (it.represents_contributing_render_surface()) {
 642         // Surfaces aren't used by the tile raster code, so they can have
 643         // occlusion regardless of replicas.
 644         Occlusion occlusion =
 645             occlusion_tracker.GetCurrentOcclusionForContributingSurface(
 646                 it->render_surface()->draw_transform());
 647         it->render_surface()->set_occlusion_in_content_space(occlusion);
 648         // Masks are used to draw the contributing surface, so should have
 649         // the same occlusion as the surface (nothing inside the surface
 650         // occludes them).
 651         if (LayerImpl* mask = it->mask_layer()) {
 652           Occlusion mask_occlusion =
 653               inside_replica
 654                   ? Occlusion()
 655                   : occlusion_tracker.GetCurrentOcclusionForContributingSurface(
 656                         it->render_surface()->draw_transform() *
 657                         it->draw_transform());
 658           mask->draw_properties().occlusion_in_content_space = mask_occlusion;
 659         }
 660         if (LayerImpl* replica = it->replica_layer()) {
 661           if (LayerImpl* mask = replica->mask_layer())
 662             mask->draw_properties().occlusion_in_content_space = Occlusion();
 663         }
 664       }
 665
 666       occlusion_tracker.LeaveLayer(it);
 667     }
 668
 669     unoccluded_screen_space_region_ =
 670         occlusion_tracker.ComputeVisibleRegionInScreen();
 671   }
 672
 673   // It'd be ideal if this could be done earlier, but when the raster source
 674   // is updated from the main thread during push properties, update draw
 675   // properties has not occurred yet and so it's not clear whether or not the
 676   // layer can or cannot use lcd text.  So, this is the cleanup pass to
 677   // determine if the raster source needs to be replaced with a non-lcd
 678   // raster source due to draw properties.
 679   if (update_lcd_text) {
 680     // TODO(enne): Make LTHI::sync_tree return this value.
 681     LayerTreeImpl* sync_tree =
 682         layer_tree_host_impl_->proxy()->CommitToActiveTree()
 683             ? layer_tree_host_impl_->active_tree()
 684             : layer_tree_host_impl_->pending_tree();
 685     // If this is not the sync tree, then it is not safe to update lcd text
 686     // as it causes invalidations and the tiles may be in use.
 687     DCHECK_EQ(this, sync_tree);
 688     for (const auto& layer : picture_layers_)
 689       layer->UpdateCanUseLCDTextAfterCommit();
 690   }
 691
 692   {
 693     TRACE_EVENT_BEGIN2("cc", "LayerTreeImpl::UpdateDrawProperties::UpdateTiles",
 694                        "IsActive", IsActiveTree(), "SourceFrameNumber",
 695                        source_frame_number_);
 696     const bool resourceless_software_draw =
 697         (layer_tree_host_impl_->GetDrawMode() ==
 698          DRAW_MODE_RESOURCELESS_SOFTWARE);
 699     size_t layers_updated_count = 0;
 700     bool tile_priorities_updated = false;
 701     for (PictureLayerImpl* layer : picture_layers_) {
 702       if (!layer->IsDrawnRenderSurfaceLayerListMember())
 703         continue;
 704       ++layers_updated_count;
 705       tile_priorities_updated |= layer->UpdateTiles(resourceless_software_draw);
 706     }
 707
 708     if (tile_priorities_updated)
 709       DidModifyTilePriorities();
 710
 711     TRACE_EVENT_END1("cc", "LayerTreeImpl::UpdateTilePriorities",
 712                      "layers_updated_count", layers_updated_count);
 713   }
 714
 715   DCHECK(!needs_update_draw_properties_) <<
 716       "CalcDrawProperties should not set_needs_update_draw_properties()";
 717   return true;
 718 }
 719
 720 void LayerTreeImpl::BuildPropertyTreesForTesting() {
 721   PropertyTreeBuilder::BuildPropertyTrees(
 722       root_layer_.get(), page_scale_layer_, current_page_scale_factor(),
 723       device_scale_factor(), gfx::Rect(DrawViewportSize()),
 724       layer_tree_host_impl_->DrawTransform(), &property_trees_);
 725 }
 726
 727 const LayerImplList& LayerTreeImpl::RenderSurfaceLayerList() const {
 728   // If this assert triggers, then the list is dirty.
 729   DCHECK(!needs_update_draw_properties_);
 730   return render_surface_layer_list_;
 731 }
 732
 733 const Region& LayerTreeImpl::UnoccludedScreenSpaceRegion() const {
 734   // If this assert triggers, then the render_surface_layer_list_ is dirty, so
 735   // the unoccluded_screen_space_region_ is not valid anymore.
 736   DCHECK(!needs_update_draw_properties_);
 737   return unoccluded_screen_space_region_;
 738 }
 739
 740 gfx::Size LayerTreeImpl::ScrollableSize() const {
 741   LayerImpl* root_scroll_layer = OuterViewportScrollLayer()
 742                                      ? OuterViewportScrollLayer()
 743                                      : InnerViewportScrollLayer();
 744   if (!root_scroll_layer || root_scroll_layer->children().empty())
 745     return gfx::Size();
 746   return root_scroll_layer->children()[0]->bounds();
 747 }
 748
 749 LayerImpl* LayerTreeImpl::LayerById(int id) {
 750   LayerIdMap::iterator iter = layer_id_map_.find(id);
 751   return iter != layer_id_map_.end() ? iter->second : NULL;
 752 }
 753
 754 void LayerTreeImpl::RegisterLayer(LayerImpl* layer) {
 755   DCHECK(!LayerById(layer->id()));
 756   layer_id_map_[layer->id()] = layer;
 757 }
 758
 759 void LayerTreeImpl::UnregisterLayer(LayerImpl* layer) {
 760   DCHECK(LayerById(layer->id()));
 761   layer_id_map_.erase(layer->id());
 762 }
 763
 764 size_t LayerTreeImpl::NumLayers() {
 765   return layer_id_map_.size();
 766 }
 767
 768 void LayerTreeImpl::PushPersistedState(LayerTreeImpl* pending_tree) {
 769   pending_tree->SetCurrentlyScrollingLayer(
 770       LayerTreeHostCommon::FindLayerInSubtree(pending_tree->root_layer(),
 771           currently_scrolling_layer_ ? currently_scrolling_layer_->id() : 0));
 772 }
 773
 774 void LayerTreeImpl::DidBecomeActive() {
 775   if (next_activation_forces_redraw_) {
 776     layer_tree_host_impl_->SetFullRootLayerDamage();
 777     next_activation_forces_redraw_ = false;
 778   }
 779
 780   if (scrolling_layer_id_from_previous_tree_) {
 781     currently_scrolling_layer_ = LayerTreeHostCommon::FindLayerInSubtree(
 782         root_layer(), scrolling_layer_id_from_previous_tree_);
 783   }
 784
 785   // Always reset this flag on activation, as we would only have activated
 786   // if we were in a good state.
 787   layer_tree_host_impl_->ResetRequiresHighResToDraw();
 788
 789   if (root_layer()) {
 790     LayerTreeHostCommon::CallFunctionForSubtree(
 791         root_layer(), [](LayerImpl* layer) { layer->DidBecomeActive(); });
 792   }
 793
 794   for (auto* swap_promise : swap_promise_list_)
 795     swap_promise->DidActivate();
 796   devtools_instrumentation::DidActivateLayerTree(layer_tree_host_impl_->id(),
 797                                                  source_frame_number_);
 798 }
 799
 800 bool LayerTreeImpl::ContentsTexturesPurged() const {
 801   return contents_textures_purged_;
 802 }
 803
 804 void LayerTreeImpl::SetContentsTexturesPurged() {
 805   if (contents_textures_purged_)
 806     return;
 807   contents_textures_purged_ = true;
 808   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 809 }
 810
 811 void LayerTreeImpl::ResetContentsTexturesPurged() {
 812   if (!contents_textures_purged_)
 813     return;
 814   contents_textures_purged_ = false;
 815   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 816 }
 817
 818 bool LayerTreeImpl::RequiresHighResToDraw() const {
 819   return layer_tree_host_impl_->RequiresHighResToDraw();
 820 }
 821
 822 bool LayerTreeImpl::ViewportSizeInvalid() const {
 823   return viewport_size_invalid_;
 824 }
 825
 826 void LayerTreeImpl::SetViewportSizeInvalid() {
 827   viewport_size_invalid_ = true;
 828   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 829 }
 830
 831 void LayerTreeImpl::ResetViewportSizeInvalid() {
 832   viewport_size_invalid_ = false;
 833   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 834 }
 835
 836 Proxy* LayerTreeImpl::proxy() const {
 837   return layer_tree_host_impl_->proxy();
 838 }
 839
 840 const LayerTreeSettings& LayerTreeImpl::settings() const {
 841   return layer_tree_host_impl_->settings();
 842 }
 843
 844 const LayerTreeDebugState& LayerTreeImpl::debug_state() const {
 845   return layer_tree_host_impl_->debug_state();
 846 }
 847
 848 const RendererCapabilitiesImpl& LayerTreeImpl::GetRendererCapabilities() const {
 849   return layer_tree_host_impl_->GetRendererCapabilities();
 850 }
 851
 852 ContextProvider* LayerTreeImpl::context_provider() const {
 853   return output_surface()->context_provider();
 854 }
 855
 856 OutputSurface* LayerTreeImpl::output_surface() const {
 857   return layer_tree_host_impl_->output_surface();
 858 }
 859
 860 ResourceProvider* LayerTreeImpl::resource_provider() const {
 861   return layer_tree_host_impl_->resource_provider();
 862 }
 863
 864 TileManager* LayerTreeImpl::tile_manager() const {
 865   return layer_tree_host_impl_->tile_manager();
 866 }
 867
 868 FrameRateCounter* LayerTreeImpl::frame_rate_counter() const {
 869   return layer_tree_host_impl_->fps_counter();
 870 }
 871
 872 PaintTimeCounter* LayerTreeImpl::paint_time_counter() const {
 873   return layer_tree_host_impl_->paint_time_counter();
 874 }
 875
 876 MemoryHistory* LayerTreeImpl::memory_history() const {
 877   return layer_tree_host_impl_->memory_history();
 878 }
 879
 880 gfx::Size LayerTreeImpl::device_viewport_size() const {
 881   return layer_tree_host_impl_->device_viewport_size();
 882 }
 883
 884 float LayerTreeImpl::device_scale_factor() const {
 885   return layer_tree_host_impl_->device_scale_factor();
 886 }
 887
 888 DebugRectHistory* LayerTreeImpl::debug_rect_history() const {
 889   return layer_tree_host_impl_->debug_rect_history();
 890 }
 891
 892 bool LayerTreeImpl::IsActiveTree() const {
 893   return layer_tree_host_impl_->active_tree() == this;
 894 }
 895
 896 bool LayerTreeImpl::IsPendingTree() const {
 897   return layer_tree_host_impl_->pending_tree() == this;
 898 }
 899
 900 bool LayerTreeImpl::IsRecycleTree() const {
 901   return layer_tree_host_impl_->recycle_tree() == this;
 902 }
 903
 904 bool LayerTreeImpl::IsSyncTree() const {
 905   return layer_tree_host_impl_->sync_tree() == this;
 906 }
 907
 908 LayerImpl* LayerTreeImpl::FindActiveTreeLayerById(int id) {
 909   LayerTreeImpl* tree = layer_tree_host_impl_->active_tree();
 910   if (!tree)
 911     return NULL;
 912   return tree->LayerById(id);
 913 }
 914
 915 LayerImpl* LayerTreeImpl::FindPendingTreeLayerById(int id) {
 916   LayerTreeImpl* tree = layer_tree_host_impl_->pending_tree();
 917   if (!tree)
 918     return NULL;
 919   return tree->LayerById(id);
 920 }
 921
 922 bool LayerTreeImpl::PinchGestureActive() const {
 923   return layer_tree_host_impl_->pinch_gesture_active();
 924 }
 925
 926 BeginFrameArgs LayerTreeImpl::CurrentBeginFrameArgs() const {
 927   return layer_tree_host_impl_->CurrentBeginFrameArgs();
 928 }
 929
 930 base::TimeDelta LayerTreeImpl::CurrentBeginFrameInterval() const {
 931   return layer_tree_host_impl_->CurrentBeginFrameInterval();
 932 }
 933
 934 void LayerTreeImpl::SetNeedsCommit() {
 935   layer_tree_host_impl_->SetNeedsCommit();
 936 }
 937
 938 gfx::Rect LayerTreeImpl::DeviceViewport() const {
 939   return layer_tree_host_impl_->DeviceViewport();
 940 }
 941
 942 gfx::Size LayerTreeImpl::DrawViewportSize() const {
 943   return layer_tree_host_impl_->DrawViewportSize();
 944 }
 945
 946 const gfx::Rect LayerTreeImpl::ViewportRectForTilePriority() const {
 947   return layer_tree_host_impl_->ViewportRectForTilePriority();
 948 }
 949
 950 scoped_ptr<ScrollbarAnimationController>
 951 LayerTreeImpl::CreateScrollbarAnimationController(LayerImpl* scrolling_layer) {
 952   DCHECK(settings().scrollbar_fade_delay_ms);
 953   DCHECK(settings().scrollbar_fade_duration_ms);
 954   base::TimeDelta delay =
 955       base::TimeDelta::FromMilliseconds(settings().scrollbar_fade_delay_ms);
 956   base::TimeDelta resize_delay = base::TimeDelta::FromMilliseconds(
 957       settings().scrollbar_fade_resize_delay_ms);
 958   base::TimeDelta duration =
 959       base::TimeDelta::FromMilliseconds(settings().scrollbar_fade_duration_ms);
 960   switch (settings().scrollbar_animator) {
 961     case LayerTreeSettings::LINEAR_FADE: {
 962       return ScrollbarAnimationControllerLinearFade::Create(
 963           scrolling_layer,
 964           layer_tree_host_impl_,
 965           delay,
 966           resize_delay,
 967           duration);
 968     }
 969     case LayerTreeSettings::THINNING: {
 970       return ScrollbarAnimationControllerThinning::Create(scrolling_layer,
 971                                                           layer_tree_host_impl_,
 972                                                           delay,
 973                                                           resize_delay,
 974                                                           duration);
 975     }
 976     case LayerTreeSettings::NO_ANIMATOR:
 977       NOTREACHED();
 978       break;
 979   }
 980   return nullptr;
 981 }
 982
 983 void LayerTreeImpl::DidAnimateScrollOffset() {
 984   layer_tree_host_impl_->DidAnimateScrollOffset();
 985 }
 986
 987 bool LayerTreeImpl::use_gpu_rasterization() const {
 988   return layer_tree_host_impl_->use_gpu_rasterization();
 989 }
 990
 991 GpuRasterizationStatus LayerTreeImpl::GetGpuRasterizationStatus() const {
 992   return layer_tree_host_impl_->gpu_rasterization_status();
 993 }
 994
 995 bool LayerTreeImpl::create_low_res_tiling() const {
 996   return layer_tree_host_impl_->create_low_res_tiling();
 997 }
 998
 999 void LayerTreeImpl::SetNeedsRedraw() {
1000   layer_tree_host_impl_->SetNeedsRedraw();
1001 }
1002
1003 AnimationRegistrar* LayerTreeImpl::GetAnimationRegistrar() const {
1004   return layer_tree_host_impl_->animation_registrar();
1005 }
1006
1007 void LayerTreeImpl::GetAllPrioritizedTilesForTracing(
1008     std::vector<PrioritizedTile>* prioritized_tiles) const {
1009   typedef LayerIterator<LayerImpl> LayerIteratorType;
1010   LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list_);
1011   for (LayerIteratorType it =
1012            LayerIteratorType::Begin(&render_surface_layer_list_);
1013        it != end;
1014        ++it) {
1015     if (!it.represents_itself())
1016       continue;
1017     LayerImpl* layer_impl = *it;
1018     layer_impl->GetAllPrioritizedTilesForTracing(prioritized_tiles);
1019   }
1020 }
1021
1022 void LayerTreeImpl::AsValueInto(base::trace_event::TracedValue* state) const {
1023   TracedValue::MakeDictIntoImplicitSnapshot(state, "cc::LayerTreeImpl", this);
1024   state->SetInteger("source_frame_number", source_frame_number_);
1025
1026   state->BeginDictionary("root_layer");
1027   root_layer_->AsValueInto(state);
1028   state->EndDictionary();
1029
1030   state->BeginArray("render_surface_layer_list");
1031   typedef LayerIterator<LayerImpl> LayerIteratorType;
1032   LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list_);
1033   for (LayerIteratorType it = LayerIteratorType::Begin(
1034            &render_surface_layer_list_); it != end; ++it) {
1035     if (!it.represents_itself())
1036       continue;
1037     TracedValue::AppendIDRef(*it, state);
1038   }
1039   state->EndArray();
1040
1041   state->BeginArray("swap_promise_trace_ids");
1042   for (auto* swap_promise : swap_promise_list_)
1043     state->AppendDouble(swap_promise->TraceId());
1044   state->EndArray();
1045 }
1046
1047 void LayerTreeImpl::SetRootLayerScrollOffsetDelegate(
1048     LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate) {
1049   if (root_layer_scroll_offset_delegate_ == root_layer_scroll_offset_delegate)
1050     return;
1051
1052   root_layer_scroll_offset_delegate_ = root_layer_scroll_offset_delegate;
1053
1054   if (root_layer_scroll_offset_delegate_) {
1055     root_layer_scroll_offset_delegate_->UpdateRootLayerState(
1056         TotalScrollOffset(), TotalMaxScrollOffset(), ScrollableSize(),
1057         current_page_scale_factor(), min_page_scale_factor(),
1058         max_page_scale_factor());
1059
1060     DistributeRootScrollOffset();
1061   }
1062 }
1063
1064 void LayerTreeImpl::UpdateRootScrollOffsetDelegate() {
1065   DCHECK(root_layer_scroll_offset_delegate_);
1066
1067   gfx::ScrollOffset offset = InnerViewportScrollLayer()->CurrentScrollOffset();
1068
1069   if (OuterViewportScrollLayer())
1070     offset += OuterViewportScrollLayer()->CurrentScrollOffset();
1071
1072   root_layer_scroll_offset_delegate_->UpdateRootLayerState(
1073       offset, TotalMaxScrollOffset(), ScrollableSize(),
1074       current_page_scale_factor(), min_page_scale_factor(),
1075       max_page_scale_factor());
1076 }
1077
1078 void LayerTreeImpl::DistributeRootScrollOffset() {
1079   if (!root_layer_scroll_offset_delegate_)
1080     return;
1081
1082   gfx::ScrollOffset root_offset =
1083       root_layer_scroll_offset_delegate_->GetTotalScrollOffset();
1084
1085   if (!InnerViewportScrollLayer())
1086     return;
1087
1088   DCHECK(OuterViewportScrollLayer());
1089
1090   // If we get here, we have both inner/outer viewports, and need to distribute
1091   // the scroll offset between them.
1092   gfx::ScrollOffset inner_viewport_offset =
1093       InnerViewportScrollLayer()->CurrentScrollOffset();
1094   gfx::ScrollOffset outer_viewport_offset =
1095       OuterViewportScrollLayer()->CurrentScrollOffset();
1096
1097   // It may be nothing has changed.
1098   if (inner_viewport_offset + outer_viewport_offset == root_offset)
1099     return;
1100
1101   gfx::ScrollOffset max_outer_viewport_scroll_offset =
1102       OuterViewportScrollLayer()->MaxScrollOffset();
1103
1104   outer_viewport_offset = root_offset - inner_viewport_offset;
1105   outer_viewport_offset.SetToMin(max_outer_viewport_scroll_offset);
1106   outer_viewport_offset.SetToMax(gfx::ScrollOffset());
1107
1108   OuterViewportScrollLayer()->SetCurrentScrollOffsetFromDelegate(
1109       outer_viewport_offset);
1110   inner_viewport_offset = root_offset - outer_viewport_offset;
1111   InnerViewportScrollLayer()->SetCurrentScrollOffsetFromDelegate(
1112       inner_viewport_offset);
1113
1114   UpdateRootScrollOffsetDelegate();
1115 }
1116
1117 void LayerTreeImpl::QueueSwapPromise(scoped_ptr<SwapPromise> swap_promise) {
1118   DCHECK(swap_promise);
1119   swap_promise_list_.push_back(swap_promise.Pass());
1120 }
1121
1122 void LayerTreeImpl::PassSwapPromises(
1123     ScopedPtrVector<SwapPromise>* new_swap_promise) {
1124   swap_promise_list_.insert_and_take(swap_promise_list_.end(),
1125                                      new_swap_promise);
1126   new_swap_promise->clear();
1127 }
1128
1129 void LayerTreeImpl::FinishSwapPromises(CompositorFrameMetadata* metadata) {
1130   for (auto* swap_promise : swap_promise_list_)
1131     swap_promise->DidSwap(metadata);
1132   swap_promise_list_.clear();
1133 }
1134
1135 void LayerTreeImpl::BreakSwapPromises(SwapPromise::DidNotSwapReason reason) {
1136   for (auto* swap_promise : swap_promise_list_)
1137     swap_promise->DidNotSwap(reason);
1138   swap_promise_list_.clear();
1139 }
1140
1141 void LayerTreeImpl::DidModifyTilePriorities() {
1142   layer_tree_host_impl_->DidModifyTilePriorities();
1143 }
1144
1145 void LayerTreeImpl::set_ui_resource_request_queue(
1146     const UIResourceRequestQueue& queue) {
1147   ui_resource_request_queue_ = queue;
1148 }
1149
1150 ResourceId LayerTreeImpl::ResourceIdForUIResource(UIResourceId uid) const {
1151   return layer_tree_host_impl_->ResourceIdForUIResource(uid);
1152 }
1153
1154 bool LayerTreeImpl::IsUIResourceOpaque(UIResourceId uid) const {
1155   return layer_tree_host_impl_->IsUIResourceOpaque(uid);
1156 }
1157
1158 void LayerTreeImpl::ProcessUIResourceRequestQueue() {
1159   for (const auto& req : ui_resource_request_queue_) {
1160     switch (req.GetType()) {
1161       case UIResourceRequest::UI_RESOURCE_CREATE:
1162         layer_tree_host_impl_->CreateUIResource(req.GetId(), req.GetBitmap());
1163         break;
1164       case UIResourceRequest::UI_RESOURCE_DELETE:
1165         layer_tree_host_impl_->DeleteUIResource(req.GetId());
1166         break;
1167       case UIResourceRequest::UI_RESOURCE_INVALID_REQUEST:
1168         NOTREACHED();
1169         break;
1170     }
1171   }
1172   ui_resource_request_queue_.clear();
1173
1174   // If all UI resource evictions were not recreated by processing this queue,
1175   // then another commit is required.
1176   if (layer_tree_host_impl_->EvictedUIResourcesExist())
1177     layer_tree_host_impl_->SetNeedsCommit();
1178 }
1179
1180 void LayerTreeImpl::RegisterPictureLayerImpl(PictureLayerImpl* layer) {
1181   DCHECK(std::find(picture_layers_.begin(), picture_layers_.end(), layer) ==
1182          picture_layers_.end());
1183   picture_layers_.push_back(layer);
1184 }
1185
1186 void LayerTreeImpl::UnregisterPictureLayerImpl(PictureLayerImpl* layer) {
1187   std::vector<PictureLayerImpl*>::iterator it =
1188       std::find(picture_layers_.begin(), picture_layers_.end(), layer);
1189   DCHECK(it != picture_layers_.end());
1190   picture_layers_.erase(it);
1191 }
1192
1193 void LayerTreeImpl::AddLayerWithCopyOutputRequest(LayerImpl* layer) {
1194   // Only the active tree needs to know about layers with copy requests, as
1195   // they are aborted if not serviced during draw.
1196   DCHECK(IsActiveTree());
1197
1198   // DCHECK(std::find(layers_with_copy_output_request_.begin(),
1199   //                 layers_with_copy_output_request_.end(),
1200   //                 layer) == layers_with_copy_output_request_.end());
1201   // TODO(danakj): Remove this once crash is found crbug.com/309777
1202   for (size_t i = 0; i < layers_with_copy_output_request_.size(); ++i) {
1203     CHECK(layers_with_copy_output_request_[i] != layer)
1204         << i << " of " << layers_with_copy_output_request_.size();
1205   }
1206   layers_with_copy_output_request_.push_back(layer);
1207 }
1208
1209 void LayerTreeImpl::RemoveLayerWithCopyOutputRequest(LayerImpl* layer) {
1210   // Only the active tree needs to know about layers with copy requests, as
1211   // they are aborted if not serviced during draw.
1212   DCHECK(IsActiveTree());
1213
1214   std::vector<LayerImpl*>::iterator it = std::find(
1215       layers_with_copy_output_request_.begin(),
1216       layers_with_copy_output_request_.end(),
1217       layer);
1218   DCHECK(it != layers_with_copy_output_request_.end());
1219   layers_with_copy_output_request_.erase(it);
1220
1221   // TODO(danakj): Remove this once crash is found crbug.com/309777
1222   for (size_t i = 0; i < layers_with_copy_output_request_.size(); ++i) {
1223     CHECK(layers_with_copy_output_request_[i] != layer)
1224         << i << " of " << layers_with_copy_output_request_.size();
1225   }
1226 }
1227
1228 const std::vector<LayerImpl*>& LayerTreeImpl::LayersWithCopyOutputRequest()
1229     const {
1230   // Only the active tree needs to know about layers with copy requests, as
1231   // they are aborted if not serviced during draw.
1232   DCHECK(IsActiveTree());
1233
1234   return layers_with_copy_output_request_;
1235 }
1236
1237 template <typename LayerType>
1238 static inline bool LayerClipsSubtree(LayerType* layer) {
1239   return layer->masks_to_bounds() || layer->mask_layer();
1240 }
1241
1242 static bool PointHitsRect(
1243     const gfx::PointF& screen_space_point,
1244     const gfx::Transform& local_space_to_screen_space_transform,
1245     const gfx::RectF& local_space_rect,
1246     float* distance_to_camera) {
1247   // If the transform is not invertible, then assume that this point doesn't hit
1248   // this rect.
1249   gfx::Transform inverse_local_space_to_screen_space(
1250       gfx::Transform::kSkipInitialization);
1251   if (!local_space_to_screen_space_transform.GetInverse(
1252           &inverse_local_space_to_screen_space))
1253     return false;
1254
1255   // Transform the hit test point from screen space to the local space of the
1256   // given rect.
1257   bool clipped = false;
1258   gfx::Point3F planar_point = MathUtil::ProjectPoint3D(
1259       inverse_local_space_to_screen_space, screen_space_point, &clipped);
1260   gfx::PointF hit_test_point_in_local_space =
1261       gfx::PointF(planar_point.x(), planar_point.y());
1262
1263   // If ProjectPoint could not project to a valid value, then we assume that
1264   // this point doesn't hit this rect.
1265   if (clipped)
1266     return false;
1267
1268   if (!local_space_rect.Contains(hit_test_point_in_local_space))
1269     return false;
1270
1271   if (distance_to_camera) {
1272     // To compute the distance to the camera, we have to take the planar point
1273     // and pull it back to world space and compute the displacement along the
1274     // z-axis.
1275     gfx::Point3F planar_point_in_screen_space(planar_point);
1276     local_space_to_screen_space_transform.TransformPoint(
1277         &planar_point_in_screen_space);
1278     *distance_to_camera = planar_point_in_screen_space.z();
1279   }
1280
1281   return true;
1282 }
1283
1284 static bool PointHitsRegion(const gfx::PointF& screen_space_point,
1285                             const gfx::Transform& screen_space_transform,
1286                             const Region& layer_space_region) {
1287   // If the transform is not invertible, then assume that this point doesn't hit
1288   // this region.
1289   gfx::Transform inverse_screen_space_transform(
1290       gfx::Transform::kSkipInitialization);
1291   if (!screen_space_transform.GetInverse(&inverse_screen_space_transform))
1292     return false;
1293
1294   // Transform the hit test point from screen space to the local space of the
1295   // given region.
1296   bool clipped = false;
1297   gfx::PointF hit_test_point_in_layer_space = MathUtil::ProjectPoint(
1298       inverse_screen_space_transform, screen_space_point, &clipped);
1299
1300   // If ProjectPoint could not project to a valid value, then we assume that
1301   // this point doesn't hit this region.
1302   if (clipped)
1303     return false;
1304
1305   return layer_space_region.Contains(
1306       gfx::ToRoundedPoint(hit_test_point_in_layer_space));
1307 }
1308
1309 static const LayerImpl* GetNextClippingLayer(const LayerImpl* layer) {
1310   if (layer->scroll_parent())
1311     return layer->scroll_parent();
1312   if (layer->clip_parent())
1313     return layer->clip_parent();
1314   return layer->parent();
1315 }
1316
1317 static bool PointIsClippedBySurfaceOrClipRect(
1318     const gfx::PointF& screen_space_point,
1319     const LayerImpl* layer) {
1320   // Walk up the layer tree and hit-test any render_surfaces and any layer
1321   // clip rects that are active.
1322   for (; layer; layer = GetNextClippingLayer(layer)) {
1323     if (layer->render_surface() &&
1324         !PointHitsRect(screen_space_point,
1325                        layer->render_surface()->screen_space_transform(),
1326                        layer->render_surface()->content_rect(),
1327                        NULL))
1328       return true;
1329
1330     if (LayerClipsSubtree(layer) &&
1331         !PointHitsRect(screen_space_point, layer->screen_space_transform(),
1332                        gfx::Rect(layer->bounds()), NULL))
1333       return true;
1334   }
1335
1336   // If we have finished walking all ancestors without having already exited,
1337   // then the point is not clipped by any ancestors.
1338   return false;
1339 }
1340
1341 static bool PointHitsLayer(const LayerImpl* layer,
1342                            const gfx::PointF& screen_space_point,
1343                            float* distance_to_intersection) {
1344   gfx::RectF content_rect(layer->bounds());
1345   if (!PointHitsRect(screen_space_point,
1346                      layer->screen_space_transform(),
1347                      content_rect,
1348                      distance_to_intersection))
1349     return false;
1350
1351   // At this point, we think the point does hit the layer, but we need to walk
1352   // up the parents to ensure that the layer was not clipped in such a way
1353   // that the hit point actually should not hit the layer.
1354   if (PointIsClippedBySurfaceOrClipRect(screen_space_point, layer))
1355     return false;
1356
1357   // Skip the HUD layer.
1358   if (layer == layer->layer_tree_impl()->hud_layer())
1359     return false;
1360
1361   return true;
1362 }
1363
1364 struct FindClosestMatchingLayerDataForRecursion {
1365   FindClosestMatchingLayerDataForRecursion()
1366       : closest_match(NULL),
1367         closest_distance(-std::numeric_limits<float>::infinity()) {}
1368   LayerImpl* closest_match;
1369   // Note that the positive z-axis points towards the camera, so bigger means
1370   // closer in this case, counterintuitively.
1371   float closest_distance;
1372 };
1373
1374 template <typename Functor>
1375 static void FindClosestMatchingLayer(
1376     const gfx::PointF& screen_space_point,
1377     LayerImpl* layer,
1378     const Functor& func,
1379     FindClosestMatchingLayerDataForRecursion* data_for_recursion) {
1380   size_t children_size = layer->children().size();
1381   for (size_t i = 0; i < children_size; ++i) {
1382     size_t index = children_size - 1 - i;
1383     FindClosestMatchingLayer(screen_space_point, layer->children()[index], func,
1384                              data_for_recursion);
1385   }
1386
1387   float distance_to_intersection = 0.f;
1388   if (func(layer) &&
1389       PointHitsLayer(layer, screen_space_point, &distance_to_intersection) &&
1390       ((!data_for_recursion->closest_match ||
1391         distance_to_intersection > data_for_recursion->closest_distance))) {
1392     data_for_recursion->closest_distance = distance_to_intersection;
1393     data_for_recursion->closest_match = layer;
1394   }
1395 }
1396
1397 static bool ScrollsAnyDrawnRenderSurfaceLayerListMember(LayerImpl* layer) {
1398   if (!layer->scrollable())
1399     return false;
1400   if (layer->layer_or_descendant_is_drawn())
1401     return true;
1402
1403   if (!layer->scroll_children())
1404     return false;
1405   for (std::set<LayerImpl*>::const_iterator it =
1406            layer->scroll_children()->begin();
1407        it != layer->scroll_children()->end();
1408        ++it) {
1409     if ((*it)->layer_or_descendant_is_drawn())
1410       return true;
1411   }
1412   return false;
1413 }
1414
1415 struct FindScrollingLayerFunctor {
1416   bool operator()(LayerImpl* layer) const {
1417     return ScrollsAnyDrawnRenderSurfaceLayerListMember(layer);
1418   }
1419 };
1420
1421 LayerImpl* LayerTreeImpl::FindFirstScrollingLayerThatIsHitByPoint(
1422     const gfx::PointF& screen_space_point) {
1423   FindClosestMatchingLayerDataForRecursion data_for_recursion;
1424   FindClosestMatchingLayer(screen_space_point,
1425                            root_layer(),
1426                            FindScrollingLayerFunctor(),
1427                            &data_for_recursion);
1428   return data_for_recursion.closest_match;
1429 }
1430
1431 struct HitTestVisibleScrollableOrTouchableFunctor {
1432   bool operator()(LayerImpl* layer) const {
1433     return layer->IsDrawnRenderSurfaceLayerListMember() ||
1434            ScrollsAnyDrawnRenderSurfaceLayerListMember(layer) ||
1435            !layer->touch_event_handler_region().IsEmpty() ||
1436            layer->have_wheel_event_handlers();
1437   }
1438 };
1439
1440 LayerImpl* LayerTreeImpl::FindLayerThatIsHitByPoint(
1441     const gfx::PointF& screen_space_point) {
1442   if (!root_layer())
1443     return NULL;
1444   bool update_lcd_text = false;
1445   if (!UpdateDrawProperties(update_lcd_text))
1446     return NULL;
1447   FindClosestMatchingLayerDataForRecursion data_for_recursion;
1448   FindClosestMatchingLayer(screen_space_point,
1449                            root_layer(),
1450                            HitTestVisibleScrollableOrTouchableFunctor(),
1451                            &data_for_recursion);
1452   return data_for_recursion.closest_match;
1453 }
1454
1455 static bool LayerHasTouchEventHandlersAt(const gfx::PointF& screen_space_point,
1456                                          LayerImpl* layer_impl) {
1457   if (layer_impl->touch_event_handler_region().IsEmpty())
1458     return false;
1459
1460   if (!PointHitsRegion(screen_space_point, layer_impl->screen_space_transform(),
1461                        layer_impl->touch_event_handler_region()))
1462     return false;
1463
1464   // At this point, we think the point does hit the touch event handler region
1465   // on the layer, but we need to walk up the parents to ensure that the layer
1466   // was not clipped in such a way that the hit point actually should not hit
1467   // the layer.
1468   if (PointIsClippedBySurfaceOrClipRect(screen_space_point, layer_impl))
1469     return false;
1470
1471   return true;
1472 }
1473
1474 struct FindWheelEventLayerFunctor {
1475   bool operator()(LayerImpl* layer) const {
1476     return layer->have_wheel_event_handlers();
1477   }
1478 };
1479
1480 LayerImpl* LayerTreeImpl::FindLayerWithWheelHandlerThatIsHitByPoint(
1481     const gfx::PointF& screen_space_point) {
1482   if (!root_layer())
1483     return NULL;
1484   bool update_lcd_text = false;
1485   if (!UpdateDrawProperties(update_lcd_text))
1486     return NULL;
1487   FindWheelEventLayerFunctor func;
1488   FindClosestMatchingLayerDataForRecursion data_for_recursion;
1489   FindClosestMatchingLayer(screen_space_point, root_layer(), func,
1490                            &data_for_recursion);
1491   return data_for_recursion.closest_match;
1492 }
1493
1494 struct FindTouchEventLayerFunctor {
1495   bool operator()(LayerImpl* layer) const {
1496     return LayerHasTouchEventHandlersAt(screen_space_point, layer);
1497   }
1498   const gfx::PointF screen_space_point;
1499 };
1500
1501 LayerImpl* LayerTreeImpl::FindLayerThatIsHitByPointInTouchHandlerRegion(
1502     const gfx::PointF& screen_space_point) {
1503   if (!root_layer())
1504     return NULL;
1505   bool update_lcd_text = false;
1506   if (!UpdateDrawProperties(update_lcd_text))
1507     return NULL;
1508   FindTouchEventLayerFunctor func = {screen_space_point};
1509   FindClosestMatchingLayerDataForRecursion data_for_recursion;
1510   FindClosestMatchingLayer(
1511       screen_space_point, root_layer(), func, &data_for_recursion);
1512   return data_for_recursion.closest_match;
1513 }
1514
1515 void LayerTreeImpl::RegisterSelection(const LayerSelection& selection) {
1516   selection_ = selection;
1517 }
1518
1519 static ViewportSelectionBound ComputeViewportSelectionBound(
1520     const LayerSelectionBound& layer_bound,
1521     LayerImpl* layer,
1522     float device_scale_factor) {
1523   ViewportSelectionBound viewport_bound;
1524   viewport_bound.type = layer_bound.type;
1525
1526   if (!layer || layer_bound.type == SELECTION_BOUND_EMPTY)
1527     return viewport_bound;
1528
1529   gfx::PointF layer_top = layer_bound.edge_top;
1530   gfx::PointF layer_bottom = layer_bound.edge_bottom;
1531
1532   bool clipped = false;
1533   gfx::PointF screen_top =
1534       MathUtil::MapPoint(layer->screen_space_transform(), layer_top, &clipped);
1535   gfx::PointF screen_bottom = MathUtil::MapPoint(
1536       layer->screen_space_transform(), layer_bottom, &clipped);
1537
1538   const float inv_scale = 1.f / device_scale_factor;
1539   viewport_bound.edge_top = gfx::ScalePoint(screen_top, inv_scale);
1540   viewport_bound.edge_bottom = gfx::ScalePoint(screen_bottom, inv_scale);
1541
1542   // The bottom edge point is used for visibility testing as it is the logical
1543   // focal point for bound selection handles (this may change in the future).
1544   // Shifting the visibility point fractionally inward ensures that neighboring
1545   // or logically coincident layers aligned to integral DPI coordinates will not
1546   // spuriously occlude the bound.
1547   gfx::Vector2dF visibility_offset = layer_top - layer_bottom;
1548   visibility_offset.Scale(device_scale_factor / visibility_offset.Length());
1549   gfx::PointF visibility_point = layer_bottom + visibility_offset;
1550   if (visibility_point.x() <= 0)
1551     visibility_point.set_x(visibility_point.x() + device_scale_factor);
1552   visibility_point = MathUtil::MapPoint(
1553       layer->screen_space_transform(), visibility_point, &clipped);
1554
1555   float intersect_distance = 0.f;
1556   viewport_bound.visible =
1557       PointHitsLayer(layer, visibility_point, &intersect_distance);
1558
1559   return viewport_bound;
1560 }
1561
1562 void LayerTreeImpl::GetViewportSelection(ViewportSelection* selection) {
1563   DCHECK(selection);
1564
1565   selection->start = ComputeViewportSelectionBound(
1566       selection_.start,
1567       selection_.start.layer_id ? LayerById(selection_.start.layer_id) : NULL,
1568       device_scale_factor());
1569   selection->is_editable = selection_.is_editable;
1570   selection->is_empty_text_form_control = selection_.is_empty_text_form_control;
1571   if (selection->start.type == SELECTION_BOUND_CENTER ||
1572       selection->start.type == SELECTION_BOUND_EMPTY) {
1573     selection->end = selection->start;
1574   } else {
1575     selection->end = ComputeViewportSelectionBound(
1576         selection_.end,
1577         selection_.end.layer_id ? LayerById(selection_.end.layer_id) : NULL,
1578         device_scale_factor());
1579   }
1580 }
1581
1582 void LayerTreeImpl::InputScrollAnimationFinished() {
1583   layer_tree_host_impl_->ScrollEnd();
1584 }
1585
1586 bool LayerTreeImpl::SmoothnessTakesPriority() const {
1587   return layer_tree_host_impl_->GetTreePriority() == SMOOTHNESS_TAKES_PRIORITY;
1588 }
1589
1590 BlockingTaskRunner* LayerTreeImpl::BlockingMainThreadTaskRunner() const {
1591   return proxy()->blocking_main_thread_task_runner();
1592 }
1593
1594 VideoFrameControllerClient* LayerTreeImpl::GetVideoFrameControllerClient()
1595     const {
1596   return layer_tree_host_impl_;
1597 }
1598
1599 void LayerTreeImpl::SetPendingPageScaleAnimation(
1600     scoped_ptr<PendingPageScaleAnimation> pending_animation) {
1601   pending_page_scale_animation_ = pending_animation.Pass();
1602 }
1603
1604 scoped_ptr<PendingPageScaleAnimation>
1605     LayerTreeImpl::TakePendingPageScaleAnimation() {
1606   return pending_page_scale_animation_.Pass();
1607 }
1608
1609 }  // namespace cc