cc/layers/layer_impl.cc

   1 // Copyright 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 "cc/layers/layer_impl.h"
   6
   7 #include "base/json/json_reader.h"
   8 #include "base/strings/stringprintf.h"
   9 #include "base/trace_event/trace_event.h"
  10 #include "base/trace_event/trace_event_argument.h"
  11 #include "cc/animation/animation_registrar.h"
  12 #include "cc/animation/scrollbar_animation_controller.h"
  13 #include "cc/base/math_util.h"
  14 #include "cc/base/simple_enclosed_region.h"
  15 #include "cc/debug/debug_colors.h"
  16 #include "cc/debug/layer_tree_debug_state.h"
  17 #include "cc/debug/micro_benchmark_impl.h"
  18 #include "cc/debug/traced_value.h"
  19 #include "cc/layers/layer_utils.h"
  20 #include "cc/layers/painted_scrollbar_layer_impl.h"
  21 #include "cc/output/copy_output_request.h"
  22 #include "cc/quads/debug_border_draw_quad.h"
  23 #include "cc/quads/render_pass.h"
  24 #include "cc/trees/layer_tree_host_common.h"
  25 #include "cc/trees/layer_tree_impl.h"
  26 #include "cc/trees/layer_tree_settings.h"
  27 #include "cc/trees/proxy.h"
  28 #include "ui/gfx/geometry/box_f.h"
  29 #include "ui/gfx/geometry/point_conversions.h"
  30 #include "ui/gfx/geometry/quad_f.h"
  31 #include "ui/gfx/geometry/rect_conversions.h"
  32 #include "ui/gfx/geometry/size_conversions.h"
  33 #include "ui/gfx/geometry/vector2d_conversions.h"
  34
  35 namespace cc {
  36 LayerImpl::LayerImpl(LayerTreeImpl* layer_impl, int id)
  37     : LayerImpl(layer_impl, id, new LayerImpl::SyncedScrollOffset) {
  38 }
  39
  40 LayerImpl::LayerImpl(LayerTreeImpl* tree_impl,
  41                      int id,
  42                      scoped_refptr<SyncedScrollOffset> scroll_offset)
  43     : parent_(nullptr),
  44       scroll_parent_(nullptr),
  45       clip_parent_(nullptr),
  46       mask_layer_id_(-1),
  47       replica_layer_id_(-1),
  48       layer_id_(id),
  49       layer_tree_impl_(tree_impl),
  50       scroll_offset_(scroll_offset),
  51       scroll_clip_layer_(nullptr),
  52       should_scroll_on_main_thread_(false),
  53       have_wheel_event_handlers_(false),
  54       have_scroll_event_handlers_(false),
  55       scroll_blocks_on_(SCROLL_BLOCKS_ON_NONE),
  56       user_scrollable_horizontal_(true),
  57       user_scrollable_vertical_(true),
  58       stacking_order_changed_(false),
  59       double_sided_(true),
  60       should_flatten_transform_(true),
  61       should_flatten_transform_from_property_tree_(false),
  62       layer_property_changed_(false),
  63       masks_to_bounds_(false),
  64       contents_opaque_(false),
  65       is_root_for_isolated_group_(false),
  66       use_parent_backface_visibility_(false),
  67       draw_checkerboard_for_missing_tiles_(false),
  68       draws_content_(false),
  69       hide_layer_and_subtree_(false),
  70       transform_is_invertible_(true),
  71       is_container_for_fixed_position_layers_(false),
  72       background_color_(0),
  73       opacity_(1.0),
  74       blend_mode_(SkXfermode::kSrcOver_Mode),
  75       num_descendants_that_draw_content_(0),
  76       transform_tree_index_(-1),
  77       opacity_tree_index_(-1),
  78       clip_tree_index_(-1),
  79       draw_depth_(0.f),
  80       needs_push_properties_(false),
  81       num_dependents_need_push_properties_(0),
  82       sorting_context_id_(0),
  83       current_draw_mode_(DRAW_MODE_NONE),
  84       frame_timing_requests_dirty_(false) {
  85   DCHECK_GT(layer_id_, 0);
  86   DCHECK(layer_tree_impl_);
  87   layer_tree_impl_->RegisterLayer(this);
  88   AnimationRegistrar* registrar = layer_tree_impl_->GetAnimationRegistrar();
  89   layer_animation_controller_ =
  90       registrar->GetAnimationControllerForId(layer_id_);
  91   layer_animation_controller_->AddValueObserver(this);
  92   if (IsActive()) {
  93     layer_animation_controller_->set_value_provider(this);
  94     layer_animation_controller_->set_layer_animation_delegate(this);
  95   }
  96   SetNeedsPushProperties();
  97 }
  98
  99 LayerImpl::~LayerImpl() {
 100   DCHECK_EQ(DRAW_MODE_NONE, current_draw_mode_);
 101
 102   layer_animation_controller_->RemoveValueObserver(this);
 103   layer_animation_controller_->remove_value_provider(this);
 104   layer_animation_controller_->remove_layer_animation_delegate(this);
 105
 106   if (!copy_requests_.empty() && layer_tree_impl_->IsActiveTree())
 107     layer_tree_impl()->RemoveLayerWithCopyOutputRequest(this);
 108   layer_tree_impl_->UnregisterLayer(this);
 109
 110   TRACE_EVENT_OBJECT_DELETED_WITH_ID(
 111       TRACE_DISABLED_BY_DEFAULT("cc.debug"), "cc::LayerImpl", this);
 112 }
 113
 114 void LayerImpl::AddChild(scoped_ptr<LayerImpl> child) {
 115   child->SetParent(this);
 116   DCHECK_EQ(layer_tree_impl(), child->layer_tree_impl());
 117   children_.push_back(child.Pass());
 118   layer_tree_impl()->set_needs_update_draw_properties();
 119 }
 120
 121 scoped_ptr<LayerImpl> LayerImpl::RemoveChild(LayerImpl* child) {
 122   for (OwnedLayerImplList::iterator it = children_.begin();
 123        it != children_.end();
 124        ++it) {
 125     if (*it == child) {
 126       scoped_ptr<LayerImpl> ret = children_.take(it);
 127       children_.erase(it);
 128       layer_tree_impl()->set_needs_update_draw_properties();
 129       return ret.Pass();
 130     }
 131   }
 132   return nullptr;
 133 }
 134
 135 void LayerImpl::SetParent(LayerImpl* parent) {
 136   if (parent_should_know_need_push_properties()) {
 137     if (parent_)
 138       parent_->RemoveDependentNeedsPushProperties();
 139     if (parent)
 140       parent->AddDependentNeedsPushProperties();
 141   }
 142   parent_ = parent;
 143 }
 144
 145 void LayerImpl::ClearChildList() {
 146   if (children_.empty())
 147     return;
 148
 149   children_.clear();
 150   layer_tree_impl()->set_needs_update_draw_properties();
 151 }
 152
 153 bool LayerImpl::HasAncestor(const LayerImpl* ancestor) const {
 154   if (!ancestor)
 155     return false;
 156
 157   for (const LayerImpl* layer = this; layer; layer = layer->parent()) {
 158     if (layer == ancestor)
 159       return true;
 160   }
 161
 162   return false;
 163 }
 164
 165 void LayerImpl::SetScrollParent(LayerImpl* parent) {
 166   if (scroll_parent_ == parent)
 167     return;
 168
 169   if (parent)
 170     DCHECK_EQ(layer_tree_impl()->LayerById(parent->id()), parent);
 171
 172   scroll_parent_ = parent;
 173   SetNeedsPushProperties();
 174 }
 175
 176 void LayerImpl::SetDebugInfo(
 177     scoped_refptr<base::trace_event::ConvertableToTraceFormat> other) {
 178   debug_info_ = other;
 179   SetNeedsPushProperties();
 180 }
 181
 182 void LayerImpl::SetScrollChildren(std::set<LayerImpl*>* children) {
 183   if (scroll_children_.get() == children)
 184     return;
 185   scroll_children_.reset(children);
 186   SetNeedsPushProperties();
 187 }
 188
 189 void LayerImpl::SetNumDescendantsThatDrawContent(int num_descendants) {
 190   if (num_descendants_that_draw_content_ == num_descendants)
 191     return;
 192   num_descendants_that_draw_content_ = num_descendants;
 193   SetNeedsPushProperties();
 194 }
 195
 196 void LayerImpl::SetClipParent(LayerImpl* ancestor) {
 197   if (clip_parent_ == ancestor)
 198     return;
 199
 200   clip_parent_ = ancestor;
 201   SetNeedsPushProperties();
 202 }
 203
 204 void LayerImpl::SetClipChildren(std::set<LayerImpl*>* children) {
 205   if (clip_children_.get() == children)
 206     return;
 207   clip_children_.reset(children);
 208   SetNeedsPushProperties();
 209 }
 210
 211 void LayerImpl::PassCopyRequests(ScopedPtrVector<CopyOutputRequest>* requests) {
 212   if (requests->empty())
 213     return;
 214   DCHECK(render_surface());
 215   bool was_empty = copy_requests_.empty();
 216   copy_requests_.insert_and_take(copy_requests_.end(), requests);
 217   requests->clear();
 218
 219   if (was_empty && layer_tree_impl()->IsActiveTree())
 220     layer_tree_impl()->AddLayerWithCopyOutputRequest(this);
 221   NoteLayerPropertyChangedForSubtree();
 222 }
 223
 224 void LayerImpl::TakeCopyRequestsAndTransformToTarget(
 225     ScopedPtrVector<CopyOutputRequest>* requests) {
 226   DCHECK(!copy_requests_.empty());
 227   DCHECK(layer_tree_impl()->IsActiveTree());
 228   DCHECK_EQ(render_target(), this);
 229
 230   size_t first_inserted_request = requests->size();
 231   requests->insert_and_take(requests->end(), &copy_requests_);
 232   copy_requests_.clear();
 233
 234   for (size_t i = first_inserted_request; i < requests->size(); ++i) {
 235     CopyOutputRequest* request = requests->at(i);
 236     if (!request->has_area())
 237       continue;
 238
 239     gfx::Rect request_in_layer_space = request->area();
 240     gfx::Rect request_in_content_space =
 241         LayerRectToContentRect(request_in_layer_space);
 242     request->set_area(MathUtil::MapEnclosingClippedRect(
 243         draw_properties_.target_space_transform, request_in_content_space));
 244   }
 245
 246   layer_tree_impl()->RemoveLayerWithCopyOutputRequest(this);
 247   layer_tree_impl()->set_needs_update_draw_properties();
 248 }
 249
 250 void LayerImpl::ClearRenderSurfaceLayerList() {
 251   if (render_surface_)
 252     render_surface_->ClearLayerLists();
 253 }
 254
 255 void LayerImpl::PopulateSharedQuadState(SharedQuadState* state) const {
 256   state->SetAll(
 257       draw_properties_.target_space_transform, draw_properties_.content_bounds,
 258       draw_properties_.visible_content_rect, draw_properties_.clip_rect,
 259       draw_properties_.is_clipped, draw_properties_.opacity,
 260       draw_properties_.blend_mode, sorting_context_id_);
 261 }
 262
 263 void LayerImpl::PopulateScaledSharedQuadState(SharedQuadState* state,
 264                                               float scale) const {
 265   gfx::Transform scaled_draw_transform =
 266       draw_properties_.target_space_transform;
 267   scaled_draw_transform.Scale(SK_MScalar1 / scale, SK_MScalar1 / scale);
 268   gfx::Size scaled_content_bounds =
 269       gfx::ToCeiledSize(gfx::ScaleSize(bounds(), scale));
 270   gfx::Rect scaled_visible_content_rect =
 271       gfx::ScaleToEnclosingRect(visible_content_rect(), scale);
 272   scaled_visible_content_rect.Intersect(gfx::Rect(scaled_content_bounds));
 273
 274   state->SetAll(scaled_draw_transform, scaled_content_bounds,
 275                 scaled_visible_content_rect, draw_properties().clip_rect,
 276                 draw_properties().is_clipped, draw_properties().opacity,
 277                 draw_properties().blend_mode, sorting_context_id_);
 278 }
 279
 280 bool LayerImpl::WillDraw(DrawMode draw_mode,
 281                          ResourceProvider* resource_provider) {
 282   // WillDraw/DidDraw must be matched.
 283   DCHECK_NE(DRAW_MODE_NONE, draw_mode);
 284   DCHECK_EQ(DRAW_MODE_NONE, current_draw_mode_);
 285   current_draw_mode_ = draw_mode;
 286   return true;
 287 }
 288
 289 void LayerImpl::DidDraw(ResourceProvider* resource_provider) {
 290   DCHECK_NE(DRAW_MODE_NONE, current_draw_mode_);
 291   current_draw_mode_ = DRAW_MODE_NONE;
 292 }
 293
 294 bool LayerImpl::ShowDebugBorders() const {
 295   return layer_tree_impl()->debug_state().show_debug_borders;
 296 }
 297
 298 void LayerImpl::GetDebugBorderProperties(SkColor* color, float* width) const {
 299   if (draws_content_) {
 300     *color = DebugColors::ContentLayerBorderColor();
 301     *width = DebugColors::ContentLayerBorderWidth(layer_tree_impl());
 302     return;
 303   }
 304
 305   if (masks_to_bounds_) {
 306     *color = DebugColors::MaskingLayerBorderColor();
 307     *width = DebugColors::MaskingLayerBorderWidth(layer_tree_impl());
 308     return;
 309   }
 310
 311   *color = DebugColors::ContainerLayerBorderColor();
 312   *width = DebugColors::ContainerLayerBorderWidth(layer_tree_impl());
 313 }
 314
 315 void LayerImpl::AppendDebugBorderQuad(
 316     RenderPass* render_pass,
 317     const gfx::Size& content_bounds,
 318     const SharedQuadState* shared_quad_state,
 319     AppendQuadsData* append_quads_data) const {
 320   SkColor color;
 321   float width;
 322   GetDebugBorderProperties(&color, &width);
 323   AppendDebugBorderQuad(render_pass,
 324                         content_bounds,
 325                         shared_quad_state,
 326                         append_quads_data,
 327                         color,
 328                         width);
 329 }
 330
 331 void LayerImpl::AppendDebugBorderQuad(RenderPass* render_pass,
 332                                       const gfx::Size& content_bounds,
 333                                       const SharedQuadState* shared_quad_state,
 334                                       AppendQuadsData* append_quads_data,
 335                                       SkColor color,
 336                                       float width) const {
 337   if (!ShowDebugBorders())
 338     return;
 339
 340   gfx::Rect quad_rect(content_bounds);
 341   gfx::Rect visible_quad_rect(quad_rect);
 342   DebugBorderDrawQuad* debug_border_quad =
 343       render_pass->CreateAndAppendDrawQuad<DebugBorderDrawQuad>();
 344   debug_border_quad->SetNew(
 345       shared_quad_state, quad_rect, visible_quad_rect, color, width);
 346   if (contents_opaque()) {
 347     // When opaque, draw a second inner border that is thicker than the outer
 348     // border, but more transparent.
 349     static const float kFillOpacity = 0.3f;
 350     SkColor fill_color = SkColorSetA(
 351         color, static_cast<uint8_t>(SkColorGetA(color) * kFillOpacity));
 352     float fill_width = width * 3;
 353     gfx::Rect fill_rect = quad_rect;
 354     fill_rect.Inset(fill_width / 2.f, fill_width / 2.f);
 355     if (fill_rect.IsEmpty())
 356       return;
 357     gfx::Rect visible_fill_rect =
 358         gfx::IntersectRects(visible_quad_rect, fill_rect);
 359     DebugBorderDrawQuad* fill_quad =
 360         render_pass->CreateAndAppendDrawQuad<DebugBorderDrawQuad>();
 361     fill_quad->SetNew(shared_quad_state, fill_rect, visible_fill_rect,
 362                       fill_color, fill_width);
 363   }
 364 }
 365
 366 bool LayerImpl::HasDelegatedContent() const {
 367   return false;
 368 }
 369
 370 bool LayerImpl::HasContributingDelegatedRenderPasses() const {
 371   return false;
 372 }
 373
 374 RenderPassId LayerImpl::FirstContributingRenderPassId() const {
 375   return RenderPassId(0, 0);
 376 }
 377
 378 RenderPassId LayerImpl::NextContributingRenderPassId(RenderPassId id) const {
 379   return RenderPassId(0, 0);
 380 }
 381
 382 void LayerImpl::GetContentsResourceId(ResourceProvider::ResourceId* resource_id,
 383                                       gfx::Size* resource_size) const {
 384   NOTREACHED();
 385   *resource_id = 0;
 386 }
 387
 388 gfx::Vector2dF LayerImpl::ScrollBy(const gfx::Vector2dF& scroll) {
 389   gfx::ScrollOffset adjusted_scroll(scroll);
 390   if (layer_tree_impl()->settings().use_pinch_virtual_viewport) {
 391     if (!user_scrollable_horizontal_)
 392       adjusted_scroll.set_x(0);
 393     if (!user_scrollable_vertical_)
 394       adjusted_scroll.set_y(0);
 395   }
 396   DCHECK(scrollable());
 397   gfx::ScrollOffset old_offset = CurrentScrollOffset();
 398   gfx::ScrollOffset new_offset =
 399       ClampScrollOffsetToLimits(old_offset + adjusted_scroll);
 400   SetCurrentScrollOffset(new_offset);
 401
 402   gfx::ScrollOffset unscrolled =
 403       old_offset + gfx::ScrollOffset(scroll) - new_offset;
 404   return gfx::Vector2dF(unscrolled.x(), unscrolled.y());
 405 }
 406
 407 void LayerImpl::SetScrollClipLayer(int scroll_clip_layer_id) {
 408   scroll_clip_layer_ = layer_tree_impl()->LayerById(scroll_clip_layer_id);
 409 }
 410
 411 bool LayerImpl::user_scrollable(ScrollbarOrientation orientation) const {
 412   return (orientation == HORIZONTAL) ? user_scrollable_horizontal_
 413                                      : user_scrollable_vertical_;
 414 }
 415
 416 void LayerImpl::ApplySentScrollDeltasFromAbortedCommit() {
 417   DCHECK(layer_tree_impl()->IsActiveTree());
 418   scroll_offset_->AbortCommit();
 419 }
 420
 421 InputHandler::ScrollStatus LayerImpl::TryScroll(
 422     const gfx::PointF& screen_space_point,
 423     InputHandler::ScrollInputType type,
 424     ScrollBlocksOn effective_block_mode) const {
 425   if (should_scroll_on_main_thread()) {
 426     TRACE_EVENT0("cc", "LayerImpl::TryScroll: Failed ShouldScrollOnMainThread");
 427     return InputHandler::SCROLL_ON_MAIN_THREAD;
 428   }
 429
 430   if (!screen_space_transform().IsInvertible()) {
 431     TRACE_EVENT0("cc", "LayerImpl::TryScroll: Ignored NonInvertibleTransform");
 432     return InputHandler::SCROLL_IGNORED;
 433   }
 434
 435   if (!non_fast_scrollable_region().IsEmpty()) {
 436     bool clipped = false;
 437     gfx::Transform inverse_screen_space_transform(
 438         gfx::Transform::kSkipInitialization);
 439     if (!screen_space_transform().GetInverse(&inverse_screen_space_transform)) {
 440       // TODO(shawnsingh): We shouldn't be applying a projection if screen space
 441       // transform is uninvertible here. Perhaps we should be returning
 442       // SCROLL_ON_MAIN_THREAD in this case?
 443     }
 444
 445     gfx::PointF hit_test_point_in_content_space =
 446         MathUtil::ProjectPoint(inverse_screen_space_transform,
 447                                screen_space_point,
 448                                &clipped);
 449     gfx::PointF hit_test_point_in_layer_space =
 450         gfx::ScalePoint(hit_test_point_in_content_space,
 451                         1.f / contents_scale_x(),
 452                         1.f / contents_scale_y());
 453     if (!clipped &&
 454         non_fast_scrollable_region().Contains(
 455             gfx::ToRoundedPoint(hit_test_point_in_layer_space))) {
 456       TRACE_EVENT0("cc",
 457                    "LayerImpl::tryScroll: Failed NonFastScrollableRegion");
 458       return InputHandler::SCROLL_ON_MAIN_THREAD;
 459     }
 460   }
 461
 462   if (have_scroll_event_handlers() &&
 463       effective_block_mode & SCROLL_BLOCKS_ON_SCROLL_EVENT) {
 464     TRACE_EVENT0("cc", "LayerImpl::tryScroll: Failed ScrollEventHandlers");
 465     return InputHandler::SCROLL_ON_MAIN_THREAD;
 466   }
 467
 468   if (type == InputHandler::WHEEL && have_wheel_event_handlers() &&
 469       effective_block_mode & SCROLL_BLOCKS_ON_WHEEL_EVENT) {
 470     TRACE_EVENT0("cc", "LayerImpl::tryScroll: Failed WheelEventHandlers");
 471     return InputHandler::SCROLL_ON_MAIN_THREAD;
 472   }
 473
 474   if (!scrollable()) {
 475     TRACE_EVENT0("cc", "LayerImpl::tryScroll: Ignored not scrollable");
 476     return InputHandler::SCROLL_IGNORED;
 477   }
 478
 479   gfx::ScrollOffset max_scroll_offset = MaxScrollOffset();
 480   if (max_scroll_offset.x() <= 0 && max_scroll_offset.y() <= 0) {
 481     TRACE_EVENT0("cc",
 482                  "LayerImpl::tryScroll: Ignored. Technically scrollable,"
 483                  " but has no affordance in either direction.");
 484     return InputHandler::SCROLL_IGNORED;
 485   }
 486
 487   return InputHandler::SCROLL_STARTED;
 488 }
 489
 490 gfx::Rect LayerImpl::LayerRectToContentRect(
 491     const gfx::RectF& layer_rect) const {
 492   gfx::RectF content_rect =
 493       gfx::ScaleRect(layer_rect, contents_scale_x(), contents_scale_y());
 494   // Intersect with content rect to avoid the extra pixel because for some
 495   // values x and y, ceil((x / y) * y) may be x + 1.
 496   content_rect.Intersect(gfx::Rect(content_bounds()));
 497   return gfx::ToEnclosingRect(content_rect);
 498 }
 499
 500 skia::RefPtr<SkPicture> LayerImpl::GetPicture() {
 501   return skia::RefPtr<SkPicture>();
 502 }
 503
 504 scoped_ptr<LayerImpl> LayerImpl::CreateLayerImpl(LayerTreeImpl* tree_impl) {
 505   return LayerImpl::Create(tree_impl, layer_id_, scroll_offset_);
 506 }
 507
 508 void LayerImpl::PushPropertiesTo(LayerImpl* layer) {
 509   layer->SetTransformOrigin(transform_origin_);
 510   layer->SetBackgroundColor(background_color_);
 511   layer->SetBounds(bounds_);
 512   layer->SetContentBounds(content_bounds());
 513   layer->SetContentsScale(contents_scale_x(), contents_scale_y());
 514   layer->SetDoubleSided(double_sided_);
 515   layer->SetDrawCheckerboardForMissingTiles(
 516       draw_checkerboard_for_missing_tiles_);
 517   layer->SetDrawsContent(DrawsContent());
 518   layer->SetHideLayerAndSubtree(hide_layer_and_subtree_);
 519   layer->SetHasRenderSurface(!!render_surface() || layer->HasCopyRequest());
 520   layer->SetFilters(filters());
 521   layer->SetBackgroundFilters(background_filters());
 522   layer->SetMasksToBounds(masks_to_bounds_);
 523   layer->SetShouldScrollOnMainThread(should_scroll_on_main_thread_);
 524   layer->SetHaveWheelEventHandlers(have_wheel_event_handlers_);
 525   layer->SetHaveScrollEventHandlers(have_scroll_event_handlers_);
 526   layer->SetScrollBlocksOn(scroll_blocks_on_);
 527   layer->SetNonFastScrollableRegion(non_fast_scrollable_region_);
 528   layer->SetTouchEventHandlerRegion(touch_event_handler_region_);
 529   layer->SetContentsOpaque(contents_opaque_);
 530   layer->SetOpacity(opacity_);
 531   layer->SetBlendMode(blend_mode_);
 532   layer->SetIsRootForIsolatedGroup(is_root_for_isolated_group_);
 533   layer->SetPosition(position_);
 534   layer->SetIsContainerForFixedPositionLayers(
 535       is_container_for_fixed_position_layers_);
 536   layer->SetPositionConstraint(position_constraint_);
 537   layer->SetShouldFlattenTransform(should_flatten_transform_);
 538   layer->set_should_flatten_transform_from_property_tree(
 539       should_flatten_transform_from_property_tree_);
 540   layer->SetUseParentBackfaceVisibility(use_parent_backface_visibility_);
 541   layer->SetTransformAndInvertibility(transform_, transform_is_invertible_);
 542
 543   layer->SetScrollClipLayer(scroll_clip_layer_ ? scroll_clip_layer_->id()
 544                                                : Layer::INVALID_ID);
 545   layer->set_user_scrollable_horizontal(user_scrollable_horizontal_);
 546   layer->set_user_scrollable_vertical(user_scrollable_vertical_);
 547
 548   layer->SetScrollCompensationAdjustment(scroll_compensation_adjustment_);
 549
 550   layer->PushScrollOffset(nullptr);
 551
 552   layer->Set3dSortingContextId(sorting_context_id_);
 553   layer->SetNumDescendantsThatDrawContent(num_descendants_that_draw_content_);
 554
 555   layer->set_transform_tree_index(transform_tree_index_);
 556   layer->set_opacity_tree_index(opacity_tree_index_);
 557   layer->set_clip_tree_index(clip_tree_index_);
 558   layer->set_offset_to_transform_parent(offset_to_transform_parent_);
 559
 560   LayerImpl* scroll_parent = nullptr;
 561   if (scroll_parent_) {
 562     scroll_parent = layer->layer_tree_impl()->LayerById(scroll_parent_->id());
 563     DCHECK(scroll_parent);
 564   }
 565
 566   layer->SetScrollParent(scroll_parent);
 567   if (scroll_children_) {
 568     std::set<LayerImpl*>* scroll_children = new std::set<LayerImpl*>;
 569     for (std::set<LayerImpl*>::iterator it = scroll_children_->begin();
 570          it != scroll_children_->end();
 571          ++it) {
 572       DCHECK_EQ((*it)->scroll_parent(), this);
 573       LayerImpl* scroll_child =
 574           layer->layer_tree_impl()->LayerById((*it)->id());
 575       DCHECK(scroll_child);
 576       scroll_children->insert(scroll_child);
 577     }
 578     layer->SetScrollChildren(scroll_children);
 579   } else {
 580     layer->SetScrollChildren(nullptr);
 581   }
 582
 583   LayerImpl* clip_parent = nullptr;
 584   if (clip_parent_) {
 585     clip_parent = layer->layer_tree_impl()->LayerById(
 586         clip_parent_->id());
 587     DCHECK(clip_parent);
 588   }
 589
 590   layer->SetClipParent(clip_parent);
 591   if (clip_children_) {
 592     std::set<LayerImpl*>* clip_children = new std::set<LayerImpl*>;
 593     for (std::set<LayerImpl*>::iterator it = clip_children_->begin();
 594         it != clip_children_->end(); ++it)
 595       clip_children->insert(layer->layer_tree_impl()->LayerById((*it)->id()));
 596     layer->SetClipChildren(clip_children);
 597   } else {
 598     layer->SetClipChildren(nullptr);
 599   }
 600
 601   layer->PassCopyRequests(&copy_requests_);
 602
 603   // If the main thread commits multiple times before the impl thread actually
 604   // draws, then damage tracking will become incorrect if we simply clobber the
 605   // update_rect here. The LayerImpl's update_rect needs to accumulate (i.e.
 606   // union) any update changes that have occurred on the main thread.
 607   update_rect_.Union(layer->update_rect());
 608   layer->SetUpdateRect(update_rect_);
 609
 610   layer->SetStackingOrderChanged(stacking_order_changed_);
 611   layer->SetDebugInfo(debug_info_);
 612
 613   if (frame_timing_requests_dirty_) {
 614     layer->PassFrameTimingRequests(&frame_timing_requests_);
 615     frame_timing_requests_dirty_ = false;
 616   }
 617
 618   // Reset any state that should be cleared for the next update.
 619   stacking_order_changed_ = false;
 620   update_rect_ = gfx::Rect();
 621   needs_push_properties_ = false;
 622   num_dependents_need_push_properties_ = 0;
 623 }
 624
 625 gfx::Vector2dF LayerImpl::FixedContainerSizeDelta() const {
 626   if (!scroll_clip_layer_)
 627     return gfx::Vector2dF();
 628
 629   gfx::Vector2dF delta_from_scroll = scroll_clip_layer_->bounds_delta();
 630
 631   // In virtual-viewport mode, we don't need to compensate for pinch zoom or
 632   // scale since the fixed container is the outer viewport, which sits below
 633   // the page scale.
 634   if (layer_tree_impl()->settings().use_pinch_virtual_viewport)
 635     return delta_from_scroll;
 636
 637   float scale_delta = layer_tree_impl()->page_scale_delta();
 638   float scale = layer_tree_impl()->current_page_scale_factor() /
 639                 layer_tree_impl()->page_scale_delta();
 640
 641   delta_from_scroll.Scale(1.f / scale);
 642
 643   // The delta-from-pinch component requires some explanation: A viewport of
 644   // size (w,h) will appear to be size (w/s,h/s) under scale s in the content
 645   // space. If s -> s' on the impl thread, where s' = s * ds, then the apparent
 646   // viewport size change in the content space due to ds is:
 647   //
 648   // (w/s',h/s') - (w/s,h/s) = (w,h)(1/s' - 1/s) = (w,h)(1 - ds)/(s ds)
 649   //
 650   gfx::Vector2dF delta_from_pinch =
 651       gfx::Rect(scroll_clip_layer_->bounds()).bottom_right() - gfx::PointF();
 652   delta_from_pinch.Scale((1.f - scale_delta) / (scale * scale_delta));
 653
 654   return delta_from_scroll + delta_from_pinch;
 655 }
 656
 657 base::DictionaryValue* LayerImpl::LayerTreeAsJson() const {
 658   base::DictionaryValue* result = new base::DictionaryValue;
 659   result->SetString("LayerType", LayerTypeAsString());
 660
 661   base::ListValue* list = new base::ListValue;
 662   list->AppendInteger(bounds().width());
 663   list->AppendInteger(bounds().height());
 664   result->Set("Bounds", list);
 665
 666   list = new base::ListValue;
 667   list->AppendDouble(position_.x());
 668   list->AppendDouble(position_.y());
 669   result->Set("Position", list);
 670
 671   const gfx::Transform& gfx_transform = draw_properties_.target_space_transform;
 672   double transform[16];
 673   gfx_transform.matrix().asColMajord(transform);
 674   list = new base::ListValue;
 675   for (int i = 0; i < 16; ++i)
 676     list->AppendDouble(transform[i]);
 677   result->Set("DrawTransform", list);
 678
 679   result->SetBoolean("DrawsContent", draws_content_);
 680   result->SetBoolean("Is3dSorted", Is3dSorted());
 681   result->SetDouble("OPACITY", opacity());
 682   result->SetBoolean("ContentsOpaque", contents_opaque_);
 683
 684   if (scrollable())
 685     result->SetBoolean("Scrollable", true);
 686
 687   if (have_wheel_event_handlers_)
 688     result->SetBoolean("WheelHandler", have_wheel_event_handlers_);
 689   if (have_scroll_event_handlers_)
 690     result->SetBoolean("ScrollHandler", have_scroll_event_handlers_);
 691   if (!touch_event_handler_region_.IsEmpty()) {
 692     scoped_ptr<base::Value> region = touch_event_handler_region_.AsValue();
 693     result->Set("TouchRegion", region.release());
 694   }
 695
 696   if (scroll_blocks_on_) {
 697     list = new base::ListValue;
 698     if (scroll_blocks_on_ & SCROLL_BLOCKS_ON_START_TOUCH)
 699       list->AppendString("StartTouch");
 700     if (scroll_blocks_on_ & SCROLL_BLOCKS_ON_WHEEL_EVENT)
 701       list->AppendString("WheelEvent");
 702     if (scroll_blocks_on_ & SCROLL_BLOCKS_ON_SCROLL_EVENT)
 703       list->AppendString("ScrollEvent");
 704     result->Set("ScrollBlocksOn", list);
 705   }
 706
 707   list = new base::ListValue;
 708   for (size_t i = 0; i < children_.size(); ++i)
 709     list->Append(children_[i]->LayerTreeAsJson());
 710   result->Set("Children", list);
 711
 712   return result;
 713 }
 714
 715 void LayerImpl::SetStackingOrderChanged(bool stacking_order_changed) {
 716   if (stacking_order_changed) {
 717     stacking_order_changed_ = true;
 718     NoteLayerPropertyChangedForSubtree();
 719   }
 720 }
 721
 722 void LayerImpl::NoteLayerPropertyChanged() {
 723   layer_property_changed_ = true;
 724   layer_tree_impl()->set_needs_update_draw_properties();
 725   SetNeedsPushProperties();
 726 }
 727
 728 void LayerImpl::NoteLayerPropertyChangedForSubtree() {
 729   layer_property_changed_ = true;
 730   layer_tree_impl()->set_needs_update_draw_properties();
 731   for (size_t i = 0; i < children_.size(); ++i)
 732     children_[i]->NoteLayerPropertyChangedForDescendantsInternal();
 733   SetNeedsPushProperties();
 734 }
 735
 736 void LayerImpl::NoteLayerPropertyChangedForDescendantsInternal() {
 737   layer_property_changed_ = true;
 738   for (size_t i = 0; i < children_.size(); ++i)
 739     children_[i]->NoteLayerPropertyChangedForDescendantsInternal();
 740 }
 741
 742 void LayerImpl::NoteLayerPropertyChangedForDescendants() {
 743   layer_tree_impl()->set_needs_update_draw_properties();
 744   for (size_t i = 0; i < children_.size(); ++i)
 745     children_[i]->NoteLayerPropertyChangedForDescendantsInternal();
 746   SetNeedsPushProperties();
 747 }
 748
 749 #if DCHECK_IS_ON()
 750 // Verify that the resource id is valid.
 751 static ResourceProvider::ResourceId ValidateResource(
 752     const ResourceProvider* provider,
 753     ResourceProvider::ResourceId id) {
 754   provider->ValidateResource(id);
 755   return id;
 756 }
 757 #endif
 758
 759 void LayerImpl::ValidateQuadResourcesInternal(DrawQuad* quad) const {
 760 #if DCHECK_IS_ON()
 761   quad->IterateResources(
 762       base::Bind(&ValidateResource, layer_tree_impl_->resource_provider()));
 763 #endif
 764 }
 765
 766 const char* LayerImpl::LayerTypeAsString() const {
 767   return "cc::LayerImpl";
 768 }
 769
 770 void LayerImpl::ResetAllChangeTrackingForSubtree() {
 771   layer_property_changed_ = false;
 772
 773   update_rect_ = gfx::Rect();
 774   damage_rect_ = gfx::RectF();
 775
 776   if (render_surface_)
 777     render_surface_->ResetPropertyChangedFlag();
 778
 779   if (mask_layer_)
 780     mask_layer_->ResetAllChangeTrackingForSubtree();
 781
 782   if (replica_layer_) {
 783     // This also resets the replica mask, if it exists.
 784     replica_layer_->ResetAllChangeTrackingForSubtree();
 785   }
 786
 787   for (size_t i = 0; i < children_.size(); ++i)
 788     children_[i]->ResetAllChangeTrackingForSubtree();
 789
 790   needs_push_properties_ = false;
 791   num_dependents_need_push_properties_ = 0;
 792 }
 793
 794 gfx::ScrollOffset LayerImpl::ScrollOffsetForAnimation() const {
 795   return CurrentScrollOffset();
 796 }
 797
 798 void LayerImpl::OnFilterAnimated(const FilterOperations& filters) {
 799   SetFilters(filters);
 800 }
 801
 802 void LayerImpl::OnOpacityAnimated(float opacity) {
 803   SetOpacity(opacity);
 804 }
 805
 806 void LayerImpl::OnTransformAnimated(const gfx::Transform& transform) {
 807   SetTransform(transform);
 808 }
 809
 810 void LayerImpl::OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset) {
 811   // Only layers in the active tree should need to do anything here, since
 812   // layers in the pending tree will find out about these changes as a
 813   // result of the shared SyncedProperty.
 814   if (!IsActive())
 815     return;
 816
 817   SetCurrentScrollOffset(scroll_offset);
 818
 819   layer_tree_impl_->DidAnimateScrollOffset();
 820 }
 821
 822 void LayerImpl::OnAnimationWaitingForDeletion() {}
 823
 824 bool LayerImpl::IsActive() const {
 825   return layer_tree_impl_->IsActiveTree();
 826 }
 827
 828 gfx::Size LayerImpl::bounds() const {
 829   gfx::Vector2d delta = gfx::ToCeiledVector2d(bounds_delta_);
 830   return gfx::Size(bounds_.width() + delta.x(),
 831                    bounds_.height() + delta.y());
 832 }
 833
 834 gfx::SizeF LayerImpl::BoundsForScrolling() const {
 835   return gfx::SizeF(bounds_.width() + bounds_delta_.x(),
 836                     bounds_.height() + bounds_delta_.y());
 837 }
 838
 839 void LayerImpl::SetBounds(const gfx::Size& bounds) {
 840   if (bounds_ == bounds)
 841     return;
 842
 843   bounds_ = bounds;
 844
 845   ScrollbarParametersDidChange(true);
 846   if (masks_to_bounds())
 847     NoteLayerPropertyChangedForSubtree();
 848   else
 849     NoteLayerPropertyChanged();
 850 }
 851
 852 void LayerImpl::SetBoundsDelta(const gfx::Vector2dF& bounds_delta) {
 853   if (bounds_delta_ == bounds_delta)
 854     return;
 855
 856   bounds_delta_ = bounds_delta;
 857
 858   ScrollbarParametersDidChange(true);
 859   if (masks_to_bounds())
 860     NoteLayerPropertyChangedForSubtree();
 861   else
 862     NoteLayerPropertyChanged();
 863 }
 864
 865 void LayerImpl::SetMaskLayer(scoped_ptr<LayerImpl> mask_layer) {
 866   int new_layer_id = mask_layer ? mask_layer->id() : -1;
 867
 868   if (mask_layer) {
 869     DCHECK_EQ(layer_tree_impl(), mask_layer->layer_tree_impl());
 870     DCHECK_NE(new_layer_id, mask_layer_id_);
 871   } else if (new_layer_id == mask_layer_id_) {
 872     return;
 873   }
 874
 875   mask_layer_ = mask_layer.Pass();
 876   mask_layer_id_ = new_layer_id;
 877   if (mask_layer_)
 878     mask_layer_->SetParent(this);
 879   NoteLayerPropertyChangedForSubtree();
 880 }
 881
 882 scoped_ptr<LayerImpl> LayerImpl::TakeMaskLayer() {
 883   mask_layer_id_ = -1;
 884   return mask_layer_.Pass();
 885 }
 886
 887 void LayerImpl::SetReplicaLayer(scoped_ptr<LayerImpl> replica_layer) {
 888   int new_layer_id = replica_layer ? replica_layer->id() : -1;
 889
 890   if (replica_layer) {
 891     DCHECK_EQ(layer_tree_impl(), replica_layer->layer_tree_impl());
 892     DCHECK_NE(new_layer_id, replica_layer_id_);
 893   } else if (new_layer_id == replica_layer_id_) {
 894     return;
 895   }
 896
 897   replica_layer_ = replica_layer.Pass();
 898   replica_layer_id_ = new_layer_id;
 899   if (replica_layer_)
 900     replica_layer_->SetParent(this);
 901   NoteLayerPropertyChangedForSubtree();
 902 }
 903
 904 scoped_ptr<LayerImpl> LayerImpl::TakeReplicaLayer() {
 905   replica_layer_id_ = -1;
 906   return replica_layer_.Pass();
 907 }
 908
 909 ScrollbarLayerImplBase* LayerImpl::ToScrollbarLayer() {
 910   return nullptr;
 911 }
 912
 913 void LayerImpl::SetDrawsContent(bool draws_content) {
 914   if (draws_content_ == draws_content)
 915     return;
 916
 917   draws_content_ = draws_content;
 918   NoteLayerPropertyChanged();
 919 }
 920
 921 void LayerImpl::SetHideLayerAndSubtree(bool hide) {
 922   if (hide_layer_and_subtree_ == hide)
 923     return;
 924
 925   hide_layer_and_subtree_ = hide;
 926   NoteLayerPropertyChangedForSubtree();
 927 }
 928
 929 void LayerImpl::SetTransformOrigin(const gfx::Point3F& transform_origin) {
 930   if (transform_origin_ == transform_origin)
 931     return;
 932   transform_origin_ = transform_origin;
 933   NoteLayerPropertyChangedForSubtree();
 934 }
 935
 936 void LayerImpl::SetBackgroundColor(SkColor background_color) {
 937   if (background_color_ == background_color)
 938     return;
 939
 940   background_color_ = background_color;
 941   NoteLayerPropertyChanged();
 942 }
 943
 944 SkColor LayerImpl::SafeOpaqueBackgroundColor() const {
 945   SkColor color = background_color();
 946   if (SkColorGetA(color) == 255 && !contents_opaque()) {
 947     color = SK_ColorTRANSPARENT;
 948   } else if (SkColorGetA(color) != 255 && contents_opaque()) {
 949     for (const LayerImpl* layer = parent(); layer;
 950          layer = layer->parent()) {
 951       color = layer->background_color();
 952       if (SkColorGetA(color) == 255)
 953         break;
 954     }
 955     if (SkColorGetA(color) != 255)
 956       color = layer_tree_impl()->background_color();
 957     if (SkColorGetA(color) != 255)
 958       color = SkColorSetA(color, 255);
 959   }
 960   return color;
 961 }
 962
 963 void LayerImpl::SetFilters(const FilterOperations& filters) {
 964   if (filters_ == filters)
 965     return;
 966
 967   filters_ = filters;
 968   NoteLayerPropertyChangedForSubtree();
 969 }
 970
 971 bool LayerImpl::FilterIsAnimating() const {
 972   return layer_animation_controller_->IsAnimatingProperty(Animation::FILTER);
 973 }
 974
 975 bool LayerImpl::FilterIsAnimatingOnImplOnly() const {
 976   Animation* filter_animation =
 977       layer_animation_controller_->GetAnimation(Animation::FILTER);
 978   return filter_animation && filter_animation->is_impl_only();
 979 }
 980
 981 void LayerImpl::SetBackgroundFilters(
 982     const FilterOperations& filters) {
 983   if (background_filters_ == filters)
 984     return;
 985
 986   background_filters_ = filters;
 987   NoteLayerPropertyChanged();
 988 }
 989
 990 void LayerImpl::SetMasksToBounds(bool masks_to_bounds) {
 991   if (masks_to_bounds_ == masks_to_bounds)
 992     return;
 993
 994   masks_to_bounds_ = masks_to_bounds;
 995   NoteLayerPropertyChangedForSubtree();
 996 }
 997
 998 void LayerImpl::SetContentsOpaque(bool opaque) {
 999   if (contents_opaque_ == opaque)
1000     return;
1001
1002   contents_opaque_ = opaque;
1003   NoteLayerPropertyChangedForSubtree();
1004 }
1005
1006 void LayerImpl::SetOpacity(float opacity) {
1007   if (opacity_ == opacity)
1008     return;
1009
1010   opacity_ = opacity;
1011   NoteLayerPropertyChangedForSubtree();
1012 }
1013
1014 bool LayerImpl::OpacityIsAnimating() const {
1015   return layer_animation_controller_->IsAnimatingProperty(Animation::OPACITY);
1016 }
1017
1018 bool LayerImpl::OpacityIsAnimatingOnImplOnly() const {
1019   Animation* opacity_animation =
1020       layer_animation_controller_->GetAnimation(Animation::OPACITY);
1021   return opacity_animation && opacity_animation->is_impl_only();
1022 }
1023
1024 void LayerImpl::SetBlendMode(SkXfermode::Mode blend_mode) {
1025   if (blend_mode_ == blend_mode)
1026     return;
1027
1028   blend_mode_ = blend_mode;
1029   NoteLayerPropertyChangedForSubtree();
1030 }
1031
1032 void LayerImpl::SetIsRootForIsolatedGroup(bool root) {
1033   if (is_root_for_isolated_group_ == root)
1034     return;
1035
1036   is_root_for_isolated_group_ = root;
1037   SetNeedsPushProperties();
1038 }
1039
1040 void LayerImpl::SetPosition(const gfx::PointF& position) {
1041   if (position_ == position)
1042     return;
1043
1044   position_ = position;
1045   NoteLayerPropertyChangedForSubtree();
1046 }
1047
1048 void LayerImpl::SetShouldFlattenTransform(bool flatten) {
1049   if (should_flatten_transform_ == flatten)
1050     return;
1051
1052   should_flatten_transform_ = flatten;
1053   NoteLayerPropertyChangedForSubtree();
1054 }
1055
1056 void LayerImpl::Set3dSortingContextId(int id) {
1057   if (id == sorting_context_id_)
1058     return;
1059   sorting_context_id_ = id;
1060   NoteLayerPropertyChangedForSubtree();
1061 }
1062
1063 void LayerImpl::PassFrameTimingRequests(
1064     std::vector<FrameTimingRequest>* requests) {
1065   frame_timing_requests_.swap(*requests);
1066   frame_timing_requests_dirty_ = true;
1067   SetNeedsPushProperties();
1068 }
1069
1070 void LayerImpl::GatherFrameTimingRequestIds(std::vector<int64_t>* request_ids) {
1071   for (const auto& request : frame_timing_requests_)
1072     request_ids->push_back(request.id());
1073 }
1074
1075 void LayerImpl::SetTransform(const gfx::Transform& transform) {
1076   if (transform_ == transform)
1077     return;
1078
1079   transform_ = transform;
1080   transform_is_invertible_ = transform_.IsInvertible();
1081   NoteLayerPropertyChangedForSubtree();
1082 }
1083
1084 void LayerImpl::SetTransformAndInvertibility(const gfx::Transform& transform,
1085                                              bool transform_is_invertible) {
1086   if (transform_ == transform) {
1087     DCHECK(transform_is_invertible_ == transform_is_invertible)
1088         << "Can't change invertibility if transform is unchanged";
1089     return;
1090   }
1091   transform_ = transform;
1092   transform_is_invertible_ = transform_is_invertible;
1093   NoteLayerPropertyChangedForSubtree();
1094 }
1095
1096 bool LayerImpl::TransformIsAnimating() const {
1097   return layer_animation_controller_->IsAnimatingProperty(Animation::TRANSFORM);
1098 }
1099
1100 bool LayerImpl::TransformIsAnimatingOnImplOnly() const {
1101   Animation* transform_animation =
1102       layer_animation_controller_->GetAnimation(Animation::TRANSFORM);
1103   return transform_animation && transform_animation->is_impl_only();
1104 }
1105
1106 void LayerImpl::SetUpdateRect(const gfx::Rect& update_rect) {
1107   update_rect_ = update_rect;
1108   SetNeedsPushProperties();
1109 }
1110
1111 void LayerImpl::AddDamageRect(const gfx::RectF& damage_rect) {
1112   damage_rect_ = gfx::UnionRects(damage_rect_, damage_rect);
1113 }
1114
1115 void LayerImpl::SetContentBounds(const gfx::Size& content_bounds) {
1116   if (this->content_bounds() == content_bounds)
1117     return;
1118
1119   draw_properties_.content_bounds = content_bounds;
1120   NoteLayerPropertyChanged();
1121 }
1122
1123 void LayerImpl::SetContentsScale(float contents_scale_x,
1124                                  float contents_scale_y) {
1125   if (this->contents_scale_x() == contents_scale_x &&
1126       this->contents_scale_y() == contents_scale_y)
1127     return;
1128
1129   draw_properties_.contents_scale_x = contents_scale_x;
1130   draw_properties_.contents_scale_y = contents_scale_y;
1131   NoteLayerPropertyChanged();
1132 }
1133
1134 bool LayerImpl::IsExternalFlingActive() const {
1135   return layer_tree_impl_->IsExternalFlingActive();
1136 }
1137
1138 void LayerImpl::SetCurrentScrollOffset(const gfx::ScrollOffset& scroll_offset) {
1139   DCHECK(IsActive());
1140   if (scroll_offset_->SetCurrent(scroll_offset))
1141     DidUpdateScrollOffset(false);
1142 }
1143
1144 void LayerImpl::SetCurrentScrollOffsetFromDelegate(
1145     const gfx::ScrollOffset& scroll_offset) {
1146   DCHECK(IsActive());
1147   if (scroll_offset_->SetCurrent(scroll_offset))
1148     DidUpdateScrollOffset(true);
1149 }
1150
1151 void LayerImpl::PushScrollOffsetFromMainThread(
1152     const gfx::ScrollOffset& scroll_offset) {
1153   PushScrollOffset(&scroll_offset);
1154 }
1155
1156 void LayerImpl::PushScrollOffsetFromMainThreadAndClobberActiveValue(
1157     const gfx::ScrollOffset& scroll_offset) {
1158   scroll_offset_->set_clobber_active_value();
1159   PushScrollOffset(&scroll_offset);
1160 }
1161
1162 gfx::ScrollOffset LayerImpl::PullDeltaForMainThread() {
1163   // TODO(miletus): Remove all this temporary flooring machinery when
1164   // Blink fully supports fractional scrolls.
1165   gfx::ScrollOffset current_offset = CurrentScrollOffset();
1166   gfx::Vector2dF current_delta = ScrollDelta();
1167   gfx::Vector2dF floored_delta(floor(current_delta.x()),
1168                                floor(current_delta.y()));
1169   gfx::Vector2dF diff_delta = floored_delta - current_delta;
1170   gfx::ScrollOffset tmp_offset = ScrollOffsetWithDelta(current_offset,
1171                                                        diff_delta);
1172   scroll_offset_->SetCurrent(tmp_offset);
1173   gfx::ScrollOffset delta = scroll_offset_->PullDeltaForMainThread();
1174   scroll_offset_->SetCurrent(current_offset);
1175   return delta;
1176 }
1177
1178 gfx::ScrollOffset LayerImpl::CurrentScrollOffset() const {
1179   return scroll_offset_->Current(IsActive());
1180 }
1181
1182 gfx::Vector2dF LayerImpl::ScrollDelta() const {
1183   if (IsActive())
1184     return gfx::Vector2dF(scroll_offset_->Delta().x(),
1185                           scroll_offset_->Delta().y());
1186   else
1187     return gfx::Vector2dF(scroll_offset_->PendingDelta().get().x(),
1188                           scroll_offset_->PendingDelta().get().y());
1189 }
1190
1191 void LayerImpl::SetScrollDelta(const gfx::Vector2dF& delta) {
1192   DCHECK(IsActive());
1193   SetCurrentScrollOffset(scroll_offset_->ActiveBase() +
1194                          gfx::ScrollOffset(delta));
1195 }
1196
1197 gfx::ScrollOffset LayerImpl::BaseScrollOffset() const {
1198   if (IsActive())
1199     return scroll_offset_->ActiveBase();
1200   else
1201     return scroll_offset_->PendingBase();
1202 }
1203
1204 void LayerImpl::PushScrollOffset(const gfx::ScrollOffset* scroll_offset) {
1205   DCHECK(scroll_offset || IsActive());
1206   bool changed = false;
1207   if (scroll_offset) {
1208     DCHECK(!IsActive() || !layer_tree_impl_->FindPendingTreeLayerById(id()));
1209     changed |= scroll_offset_->PushFromMainThread(*scroll_offset);
1210   }
1211   if (IsActive()) {
1212     changed |= scroll_offset_->PushPendingToActive();
1213   }
1214
1215   if (changed)
1216     DidUpdateScrollOffset(false);
1217 }
1218
1219 void LayerImpl::DidUpdateScrollOffset(bool is_from_root_delegate) {
1220   if (!is_from_root_delegate)
1221     layer_tree_impl()->DidUpdateScrollOffset(id());
1222   NoteLayerPropertyChangedForSubtree();
1223   ScrollbarParametersDidChange(false);
1224 }
1225
1226 void LayerImpl::SetDoubleSided(bool double_sided) {
1227   if (double_sided_ == double_sided)
1228     return;
1229
1230   double_sided_ = double_sided;
1231   NoteLayerPropertyChangedForSubtree();
1232 }
1233
1234 SimpleEnclosedRegion LayerImpl::VisibleContentOpaqueRegion() const {
1235   if (contents_opaque())
1236     return SimpleEnclosedRegion(visible_content_rect());
1237   return SimpleEnclosedRegion();
1238 }
1239
1240 void LayerImpl::DidBeginTracing() {}
1241
1242 void LayerImpl::ReleaseResources() {}
1243
1244 void LayerImpl::RecreateResources() {
1245 }
1246
1247 gfx::ScrollOffset LayerImpl::MaxScrollOffset() const {
1248   if (!scroll_clip_layer_ || bounds().IsEmpty())
1249     return gfx::ScrollOffset();
1250
1251   LayerImpl const* page_scale_layer = layer_tree_impl()->page_scale_layer();
1252   DCHECK(this != page_scale_layer);
1253   DCHECK(this != layer_tree_impl()->InnerViewportScrollLayer() ||
1254          IsContainerForFixedPositionLayers());
1255
1256   float scale_factor = 1.f;
1257   for (LayerImpl const* current_layer = this;
1258        current_layer != scroll_clip_layer_->parent();
1259        current_layer = current_layer->parent()) {
1260     if (current_layer == page_scale_layer)
1261       scale_factor = layer_tree_impl()->current_page_scale_factor();
1262   }
1263
1264   gfx::SizeF scaled_scroll_bounds =
1265       gfx::ToFlooredSize(gfx::ScaleSize(BoundsForScrolling(), scale_factor));
1266   scaled_scroll_bounds = gfx::ToFlooredSize(scaled_scroll_bounds);
1267
1268   gfx::ScrollOffset max_offset(
1269       scaled_scroll_bounds.width() - scroll_clip_layer_->bounds().width(),
1270       scaled_scroll_bounds.height() - scroll_clip_layer_->bounds().height());
1271   // We need the final scroll offset to be in CSS coords.
1272   max_offset.Scale(1 / scale_factor);
1273   max_offset.SetToMax(gfx::ScrollOffset());
1274   return max_offset;
1275 }
1276
1277 gfx::ScrollOffset LayerImpl::ClampScrollOffsetToLimits(
1278     gfx::ScrollOffset offset) const {
1279   offset.SetToMin(MaxScrollOffset());
1280   offset.SetToMax(gfx::ScrollOffset());
1281   return offset;
1282 }
1283
1284 gfx::Vector2dF LayerImpl::ClampScrollToMaxScrollOffset() {
1285   gfx::ScrollOffset old_offset = CurrentScrollOffset();
1286   gfx::ScrollOffset clamped_offset = ClampScrollOffsetToLimits(old_offset);
1287   gfx::Vector2dF delta = clamped_offset.DeltaFrom(old_offset);
1288   if (!delta.IsZero())
1289     ScrollBy(delta);
1290   return delta;
1291 }
1292
1293 void LayerImpl::SetScrollbarPosition(ScrollbarLayerImplBase* scrollbar_layer,
1294                                      LayerImpl* scrollbar_clip_layer,
1295                                      bool on_resize) const {
1296   DCHECK(scrollbar_layer);
1297   LayerImpl* page_scale_layer = layer_tree_impl()->page_scale_layer();
1298
1299   DCHECK(this != page_scale_layer);
1300   DCHECK(scrollbar_clip_layer);
1301   gfx::RectF clip_rect(gfx::PointF(),
1302                        scrollbar_clip_layer->BoundsForScrolling());
1303
1304   // See comment in MaxScrollOffset() regarding the use of the content layer
1305   // bounds here.
1306   gfx::RectF scroll_rect(gfx::PointF(), BoundsForScrolling());
1307
1308   if (scroll_rect.size().IsEmpty())
1309     return;
1310
1311   gfx::ScrollOffset current_offset;
1312   for (LayerImpl const* current_layer = this;
1313        current_layer != scrollbar_clip_layer->parent();
1314        current_layer = current_layer->parent()) {
1315     current_offset += current_layer->CurrentScrollOffset();
1316     if (current_layer == page_scale_layer) {
1317       float scale_factor = layer_tree_impl()->current_page_scale_factor();
1318       current_offset.Scale(scale_factor);
1319       scroll_rect.Scale(scale_factor);
1320     }
1321   }
1322
1323   bool scrollbar_needs_animation = false;
1324   scrollbar_needs_animation |= scrollbar_layer->SetVerticalAdjust(
1325       scrollbar_clip_layer->bounds_delta().y());
1326   if (scrollbar_layer->orientation() == HORIZONTAL) {
1327     float visible_ratio = clip_rect.width() / scroll_rect.width();
1328     scrollbar_needs_animation |=
1329         scrollbar_layer->SetCurrentPos(current_offset.x());
1330     scrollbar_needs_animation |=
1331         scrollbar_layer->SetMaximum(scroll_rect.width() - clip_rect.width());
1332     scrollbar_needs_animation |=
1333         scrollbar_layer->SetVisibleToTotalLengthRatio(visible_ratio);
1334   } else {
1335     float visible_ratio = clip_rect.height() / scroll_rect.height();
1336     bool y_offset_did_change =
1337         scrollbar_layer->SetCurrentPos(current_offset.y());
1338     scrollbar_needs_animation |= y_offset_did_change;
1339     scrollbar_needs_animation |=
1340         scrollbar_layer->SetMaximum(scroll_rect.height() - clip_rect.height());
1341     scrollbar_needs_animation |=
1342         scrollbar_layer->SetVisibleToTotalLengthRatio(visible_ratio);
1343     if (y_offset_did_change && layer_tree_impl()->IsActiveTree() &&
1344         this == layer_tree_impl()->InnerViewportScrollLayer()) {
1345       TRACE_COUNTER_ID1("cc", "scroll_offset_y", this->id(),
1346                         current_offset.y());
1347     }
1348   }
1349   if (scrollbar_needs_animation) {
1350     layer_tree_impl()->set_needs_update_draw_properties();
1351     // TODO(wjmaclean) The scrollbar animator for the pinch-zoom scrollbars
1352     // should activate for every scroll on the main frame, not just the
1353     // scrolls that move the pinch virtual viewport (i.e. trigger from
1354     // either inner or outer viewport).
1355     if (scrollbar_animation_controller_) {
1356       // Non-overlay scrollbars shouldn't trigger animations.
1357       if (scrollbar_layer->is_overlay_scrollbar())
1358         scrollbar_animation_controller_->DidScrollUpdate(on_resize);
1359     }
1360   }
1361 }
1362
1363 void LayerImpl::DidBecomeActive() {
1364   if (layer_tree_impl_->settings().scrollbar_animator ==
1365       LayerTreeSettings::NO_ANIMATOR) {
1366     return;
1367   }
1368
1369   bool need_scrollbar_animation_controller = scrollable() && scrollbars_;
1370   if (!need_scrollbar_animation_controller) {
1371     scrollbar_animation_controller_ = nullptr;
1372     return;
1373   }
1374
1375   if (scrollbar_animation_controller_)
1376     return;
1377
1378   scrollbar_animation_controller_ =
1379       layer_tree_impl_->CreateScrollbarAnimationController(this);
1380 }
1381
1382 void LayerImpl::ClearScrollbars() {
1383   if (!scrollbars_)
1384     return;
1385
1386   scrollbars_.reset(nullptr);
1387 }
1388
1389 void LayerImpl::AddScrollbar(ScrollbarLayerImplBase* layer) {
1390   DCHECK(layer);
1391   DCHECK(!scrollbars_ || scrollbars_->find(layer) == scrollbars_->end());
1392   if (!scrollbars_)
1393     scrollbars_.reset(new ScrollbarSet());
1394
1395   scrollbars_->insert(layer);
1396 }
1397
1398 void LayerImpl::RemoveScrollbar(ScrollbarLayerImplBase* layer) {
1399   DCHECK(scrollbars_);
1400   DCHECK(layer);
1401   DCHECK(scrollbars_->find(layer) != scrollbars_->end());
1402
1403   scrollbars_->erase(layer);
1404   if (scrollbars_->empty())
1405     scrollbars_ = nullptr;
1406 }
1407
1408 bool LayerImpl::HasScrollbar(ScrollbarOrientation orientation) const {
1409   if (!scrollbars_)
1410     return false;
1411
1412   for (ScrollbarSet::iterator it = scrollbars_->begin();
1413        it != scrollbars_->end();
1414        ++it)
1415     if ((*it)->orientation() == orientation)
1416       return true;
1417
1418   return false;
1419 }
1420
1421 void LayerImpl::ScrollbarParametersDidChange(bool on_resize) {
1422   if (!scrollbars_)
1423     return;
1424
1425   for (ScrollbarSet::iterator it = scrollbars_->begin();
1426        it != scrollbars_->end();
1427        ++it) {
1428     bool is_scroll_layer = (*it)->ScrollLayerId() == layer_id_;
1429     bool scroll_layer_resized = is_scroll_layer && on_resize;
1430     (*it)->ScrollbarParametersDidChange(scroll_layer_resized);
1431   }
1432 }
1433
1434 void LayerImpl::SetNeedsPushProperties() {
1435   if (needs_push_properties_)
1436     return;
1437   if (!parent_should_know_need_push_properties() && parent_)
1438     parent_->AddDependentNeedsPushProperties();
1439   needs_push_properties_ = true;
1440 }
1441
1442 void LayerImpl::AddDependentNeedsPushProperties() {
1443   DCHECK_GE(num_dependents_need_push_properties_, 0);
1444
1445   if (!parent_should_know_need_push_properties() && parent_)
1446     parent_->AddDependentNeedsPushProperties();
1447
1448   num_dependents_need_push_properties_++;
1449 }
1450
1451 void LayerImpl::RemoveDependentNeedsPushProperties() {
1452   num_dependents_need_push_properties_--;
1453   DCHECK_GE(num_dependents_need_push_properties_, 0);
1454
1455   if (!parent_should_know_need_push_properties() && parent_)
1456       parent_->RemoveDependentNeedsPushProperties();
1457 }
1458
1459 void LayerImpl::GetAllTilesAndPrioritiesForTracing(
1460     std::map<const Tile*, TilePriority>* tile_map) const {
1461 }
1462
1463 void LayerImpl::AsValueInto(base::trace_event::TracedValue* state) const {
1464   TracedValue::MakeDictIntoImplicitSnapshotWithCategory(
1465       TRACE_DISABLED_BY_DEFAULT("cc.debug"),
1466       state,
1467       "cc::LayerImpl",
1468       LayerTypeAsString(),
1469       this);
1470   state->SetInteger("layer_id", id());
1471   MathUtil::AddToTracedValue("bounds", bounds_, state);
1472
1473   state->SetDouble("opacity", opacity());
1474
1475   MathUtil::AddToTracedValue("position", position_, state);
1476
1477   state->SetInteger("draws_content", DrawsContent());
1478   state->SetInteger("gpu_memory_usage", GPUMemoryUsageInBytes());
1479
1480   MathUtil::AddToTracedValue(
1481       "scroll_offset", scroll_offset_ ? scroll_offset_->Current(IsActive())
1482                                       : gfx::ScrollOffset(),
1483       state);
1484
1485   MathUtil::AddToTracedValue("transform_origin", transform_origin_, state);
1486
1487   bool clipped;
1488   gfx::QuadF layer_quad = MathUtil::MapQuad(
1489       screen_space_transform(),
1490       gfx::QuadF(gfx::Rect(content_bounds())),
1491       &clipped);
1492   MathUtil::AddToTracedValue("layer_quad", layer_quad, state);
1493   if (!touch_event_handler_region_.IsEmpty()) {
1494     state->BeginArray("touch_event_handler_region");
1495     touch_event_handler_region_.AsValueInto(state);
1496     state->EndArray();
1497   }
1498   if (have_wheel_event_handlers_) {
1499     gfx::Rect wheel_rect(content_bounds());
1500     Region wheel_region(wheel_rect);
1501     state->BeginArray("wheel_event_handler_region");
1502     wheel_region.AsValueInto(state);
1503     state->EndArray();
1504   }
1505   if (have_scroll_event_handlers_) {
1506     gfx::Rect scroll_rect(content_bounds());
1507     Region scroll_region(scroll_rect);
1508     state->BeginArray("scroll_event_handler_region");
1509     scroll_region.AsValueInto(state);
1510     state->EndArray();
1511   }
1512   if (!non_fast_scrollable_region_.IsEmpty()) {
1513     state->BeginArray("non_fast_scrollable_region");
1514     non_fast_scrollable_region_.AsValueInto(state);
1515     state->EndArray();
1516   }
1517   if (scroll_blocks_on_) {
1518     state->SetInteger("scroll_blocks_on", scroll_blocks_on_);
1519   }
1520
1521   state->BeginArray("children");
1522   for (size_t i = 0; i < children_.size(); ++i) {
1523     state->BeginDictionary();
1524     children_[i]->AsValueInto(state);
1525     state->EndDictionary();
1526   }
1527   state->EndArray();
1528   if (mask_layer_) {
1529     state->BeginDictionary("mask_layer");
1530     mask_layer_->AsValueInto(state);
1531     state->EndDictionary();
1532   }
1533   if (replica_layer_) {
1534     state->BeginDictionary("replica_layer");
1535     replica_layer_->AsValueInto(state);
1536     state->EndDictionary();
1537   }
1538
1539   if (scroll_parent_)
1540     state->SetInteger("scroll_parent", scroll_parent_->id());
1541
1542   if (clip_parent_)
1543     state->SetInteger("clip_parent", clip_parent_->id());
1544
1545   state->SetBoolean("can_use_lcd_text", can_use_lcd_text());
1546   state->SetBoolean("contents_opaque", contents_opaque());
1547
1548   state->SetBoolean(
1549       "has_animation_bounds",
1550       layer_animation_controller()->HasAnimationThatInflatesBounds());
1551
1552   gfx::BoxF box;
1553   if (LayerUtils::GetAnimationBounds(*this, &box))
1554     MathUtil::AddToTracedValue("animation_bounds", box, state);
1555
1556   if (debug_info_.get()) {
1557     std::string str;
1558     debug_info_->AppendAsTraceFormat(&str);
1559     base::JSONReader json_reader;
1560     scoped_ptr<base::Value> debug_info_value(json_reader.ReadToValue(str));
1561
1562     if (debug_info_value->IsType(base::Value::TYPE_DICTIONARY)) {
1563       base::DictionaryValue* dictionary_value = nullptr;
1564       bool converted_to_dictionary =
1565           debug_info_value->GetAsDictionary(&dictionary_value);
1566       DCHECK(converted_to_dictionary);
1567       for (base::DictionaryValue::Iterator it(*dictionary_value); !it.IsAtEnd();
1568            it.Advance()) {
1569         state->SetValue(it.key().data(), it.value().CreateDeepCopy());
1570       }
1571     } else {
1572       NOTREACHED();
1573     }
1574   }
1575
1576   if (!frame_timing_requests_.empty()) {
1577     state->BeginArray("frame_timing_requests");
1578     for (const auto& request : frame_timing_requests_) {
1579       state->BeginDictionary();
1580       state->SetInteger("request_id", request.id());
1581       MathUtil::AddToTracedValue("request_rect", request.rect(), state);
1582       state->EndDictionary();
1583     }
1584     state->EndArray();
1585   }
1586 }
1587
1588 bool LayerImpl::IsDrawnRenderSurfaceLayerListMember() const {
1589   return draw_properties_.last_drawn_render_surface_layer_list_id ==
1590          layer_tree_impl_->current_render_surface_list_id();
1591 }
1592
1593 size_t LayerImpl::GPUMemoryUsageInBytes() const { return 0; }
1594
1595 void LayerImpl::RunMicroBenchmark(MicroBenchmarkImpl* benchmark) {
1596   benchmark->RunOnLayer(this);
1597 }
1598
1599 int LayerImpl::NumDescendantsThatDrawContent() const {
1600   return num_descendants_that_draw_content_;
1601 }
1602
1603 void LayerImpl::NotifyAnimationFinished(
1604     base::TimeTicks monotonic_time,
1605     Animation::TargetProperty target_property,
1606     int group) {
1607   if (target_property == Animation::SCROLL_OFFSET)
1608     layer_tree_impl_->InputScrollAnimationFinished();
1609 }
1610
1611 void LayerImpl::SetHasRenderSurface(bool should_have_render_surface) {
1612   if (!!render_surface() == should_have_render_surface)
1613     return;
1614
1615   SetNeedsPushProperties();
1616   layer_tree_impl()->set_needs_update_draw_properties();
1617   if (should_have_render_surface) {
1618     render_surface_ = make_scoped_ptr(new RenderSurfaceImpl(this));
1619     return;
1620   }
1621   render_surface_.reset();
1622 }
1623
1624 Region LayerImpl::GetInvalidationRegion() {
1625   return Region(update_rect_);
1626 }
1627
1628 gfx::Rect LayerImpl::GetEnclosingRectInTargetSpace() const {
1629   return MathUtil::MapEnclosingClippedRect(
1630       draw_properties_.target_space_transform,
1631       gfx::Rect(draw_properties_.content_bounds));
1632 }
1633
1634 gfx::Rect LayerImpl::GetScaledEnclosingRectInTargetSpace(float scale) const {
1635   gfx::Transform scaled_draw_transform =
1636       draw_properties_.target_space_transform;
1637   scaled_draw_transform.Scale(SK_MScalar1 / scale, SK_MScalar1 / scale);
1638   gfx::Size scaled_content_bounds =
1639       gfx::ToCeiledSize(gfx::ScaleSize(content_bounds(), scale));
1640   return MathUtil::MapEnclosingClippedRect(scaled_draw_transform,
1641                                            gfx::Rect(scaled_content_bounds));
1642 }
1643
1644 }  // namespace cc