cc/trees/layer_tree_host_impl.h

   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 #ifndef CC_TREES_LAYER_TREE_HOST_IMPL_H_
   6 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
   7
   8 #include <set>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/containers/hash_tables.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/time/time.h"
  16 #include "cc/animation/animation_events.h"
  17 #include "cc/animation/animation_registrar.h"
  18 #include "cc/animation/scrollbar_animation_controller.h"
  19 #include "cc/base/cc_export.h"
  20 #include "cc/base/synced_property.h"
  21 #include "cc/debug/frame_timing_tracker.h"
  22 #include "cc/debug/micro_benchmark_controller_impl.h"
  23 #include "cc/input/input_handler.h"
  24 #include "cc/input/layer_scroll_offset_delegate.h"
  25 #include "cc/input/top_controls_manager_client.h"
  26 #include "cc/layers/layer_lists.h"
  27 #include "cc/layers/render_pass_sink.h"
  28 #include "cc/output/begin_frame_args.h"
  29 #include "cc/output/managed_memory_policy.h"
  30 #include "cc/output/output_surface_client.h"
  31 #include "cc/output/renderer.h"
  32 #include "cc/quads/render_pass.h"
  33 #include "cc/resources/resource_provider.h"
  34 #include "cc/resources/tile_manager.h"
  35 #include "cc/resources/ui_resource_client.h"
  36 #include "cc/scheduler/commit_earlyout_reason.h"
  37 #include "cc/scheduler/draw_result.h"
  38 #include "cc/scheduler/video_frame_controller.h"
  39 #include "cc/trees/layer_tree_settings.h"
  40 #include "cc/trees/proxy.h"
  41 #include "skia/ext/refptr.h"
  42 #include "third_party/skia/include/core/SkColor.h"
  43 #include "ui/gfx/geometry/rect.h"
  44
  45 namespace gfx {
  46 class ScrollOffset;
  47 }
  48
  49 namespace cc {
  50
  51 class CompletionEvent;
  52 class CompositorFrameMetadata;
  53 class DebugRectHistory;
  54 class EvictionTilePriorityQueue;
  55 class FrameRateCounter;
  56 class LayerImpl;
  57 class LayerTreeImpl;
  58 class MemoryHistory;
  59 class PageScaleAnimation;
  60 class PaintTimeCounter;
  61 class PictureLayerImpl;
  62 class RasterTilePriorityQueue;
  63 class TileTaskWorkerPool;
  64 class RenderPassDrawQuad;
  65 class RenderingStatsInstrumentation;
  66 class ResourcePool;
  67 class ScrollElasticityHelper;
  68 class ScrollbarLayerImplBase;
  69 class SwapPromise;
  70 class SwapPromiseMonitor;
  71 class TextureMailboxDeleter;
  72 class TopControlsManager;
  73 class UIResourceBitmap;
  74 class UIResourceRequest;
  75 struct ScrollAndScaleSet;
  76 class Viewport;
  77
  78 enum class GpuRasterizationStatus {
  79   ON,
  80   ON_FORCED,
  81   OFF_DEVICE,
  82   OFF_VIEWPORT,
  83   OFF_CONTENT
  84 };
  85
  86 // LayerTreeHost->Proxy callback interface.
  87 class LayerTreeHostImplClient {
  88  public:
  89   virtual void UpdateRendererCapabilitiesOnImplThread() = 0;
  90   virtual void DidLoseOutputSurfaceOnImplThread() = 0;
  91   virtual void CommitVSyncParameters(base::TimeTicks timebase,
  92                                      base::TimeDelta interval) = 0;
  93   virtual void SetEstimatedParentDrawTime(base::TimeDelta draw_time) = 0;
  94   virtual void SetMaxSwapsPendingOnImplThread(int max) = 0;
  95   virtual void DidSwapBuffersOnImplThread() = 0;
  96   virtual void DidSwapBuffersCompleteOnImplThread() = 0;
  97   virtual void OnCanDrawStateChanged(bool can_draw) = 0;
  98   virtual void NotifyReadyToActivate() = 0;
  99   virtual void NotifyReadyToDraw() = 0;
 100   // Please call these 3 functions through
 101   // LayerTreeHostImpl's SetNeedsRedraw(), SetNeedsRedrawRect() and
 102   // SetNeedsAnimate().
 103   virtual void SetNeedsRedrawOnImplThread() = 0;
 104   virtual void SetNeedsRedrawRectOnImplThread(const gfx::Rect& damage_rect) = 0;
 105   virtual void SetNeedsAnimateOnImplThread() = 0;
 106   virtual void SetNeedsCommitOnImplThread() = 0;
 107   virtual void SetNeedsPrepareTilesOnImplThread() = 0;
 108   virtual void SetVideoNeedsBeginFrames(bool needs_begin_frames) = 0;
 109   virtual void PostAnimationEventsToMainThreadOnImplThread(
 110       scoped_ptr<AnimationEventsVector> events) = 0;
 111   // Returns true if resources were deleted by this call.
 112   virtual bool ReduceContentsTextureMemoryOnImplThread(
 113       size_t limit_bytes,
 114       int priority_cutoff) = 0;
 115   virtual bool IsInsideDraw() = 0;
 116   virtual void RenewTreePriority() = 0;
 117   virtual void PostDelayedAnimationTaskOnImplThread(const base::Closure& task,
 118                                                     base::TimeDelta delay) = 0;
 119   virtual void DidActivateSyncTree() = 0;
 120   virtual void DidPrepareTiles() = 0;
 121
 122   // Called when page scale animation has completed on the impl thread.
 123   virtual void DidCompletePageScaleAnimationOnImplThread() = 0;
 124
 125   // Called when output surface asks for a draw.
 126   virtual void OnDrawForOutputSurface() = 0;
 127
 128  protected:
 129   virtual ~LayerTreeHostImplClient() {}
 130 };
 131
 132 // LayerTreeHostImpl owns the LayerImpl trees as well as associated rendering
 133 // state.
 134 class CC_EXPORT LayerTreeHostImpl
 135     : public InputHandler,
 136       public RendererClient,
 137       public TileManagerClient,
 138       public OutputSurfaceClient,
 139       public TopControlsManagerClient,
 140       public ScrollbarAnimationControllerClient,
 141       public VideoFrameControllerClient,
 142       public base::SupportsWeakPtr<LayerTreeHostImpl> {
 143  public:
 144   static scoped_ptr<LayerTreeHostImpl> Create(
 145       const LayerTreeSettings& settings,
 146       LayerTreeHostImplClient* client,
 147       Proxy* proxy,
 148       RenderingStatsInstrumentation* rendering_stats_instrumentation,
 149       SharedBitmapManager* shared_bitmap_manager,
 150       gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
 151       TaskGraphRunner* task_graph_runner,
 152       int id);
 153   ~LayerTreeHostImpl() override;
 154
 155   // InputHandler implementation
 156   void BindToClient(InputHandlerClient* client) override;
 157   InputHandler::ScrollStatus ScrollBegin(
 158       const gfx::Point& viewport_point,
 159       InputHandler::ScrollInputType type) override;
 160   InputHandler::ScrollStatus ScrollAnimated(
 161       const gfx::Point& viewport_point,
 162       const gfx::Vector2dF& scroll_delta) override;
 163   InputHandlerScrollResult ScrollBy(
 164       const gfx::Point& viewport_point,
 165       const gfx::Vector2dF& scroll_delta) override;
 166   bool ScrollVerticallyByPage(const gfx::Point& viewport_point,
 167                               ScrollDirection direction) override;
 168   void SetRootLayerScrollOffsetDelegate(
 169       LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate) override;
 170   void OnRootLayerDelegatedScrollOffsetChanged() override;
 171   void ScrollEnd() override;
 172   InputHandler::ScrollStatus FlingScrollBegin() override;
 173   void MouseMoveAt(const gfx::Point& viewport_point) override;
 174   void PinchGestureBegin() override;
 175   void PinchGestureUpdate(float magnify_delta,
 176                           const gfx::Point& anchor) override;
 177   void PinchGestureEnd() override;
 178   void StartPageScaleAnimation(const gfx::Vector2d& target_offset,
 179                                bool anchor_point,
 180                                float page_scale,
 181                                base::TimeDelta duration);
 182   void SetNeedsAnimate() override;
 183   bool IsCurrentlyScrollingLayerAt(const gfx::Point& viewport_point,
 184                                    InputHandler::ScrollInputType type) override;
 185   bool HaveWheelEventHandlersAt(const gfx::Point& viewport_point) override;
 186   bool DoTouchEventsBlockScrollAt(const gfx::Point& viewport_port) override;
 187   scoped_ptr<SwapPromiseMonitor> CreateLatencyInfoSwapPromiseMonitor(
 188       ui::LatencyInfo* latency) override;
 189   ScrollElasticityHelper* CreateScrollElasticityHelper() override;
 190
 191   // TopControlsManagerClient implementation.
 192   float TopControlsHeight() const override;
 193   void SetCurrentTopControlsShownRatio(float offset) override;
 194   float CurrentTopControlsShownRatio() const override;
 195   void DidChangeTopControlsPosition() override;
 196   bool HaveRootScrollLayer() const override;
 197
 198   void UpdateViewportContainerSizes();
 199
 200   struct CC_EXPORT FrameData : public RenderPassSink {
 201     FrameData();
 202     ~FrameData() override;
 203     void AsValueInto(base::trace_event::TracedValue* value) const;
 204
 205     std::vector<gfx::Rect> occluding_screen_space_rects;
 206     std::vector<gfx::Rect> non_occluding_screen_space_rects;
 207     std::vector<FrameTimingTracker::FrameAndRectIds> composite_events;
 208     RenderPassList render_passes;
 209     RenderPassIdHashMap render_passes_by_id;
 210     const LayerImplList* render_surface_layer_list;
 211     LayerImplList will_draw_layers;
 212     bool has_no_damage;
 213
 214     // RenderPassSink implementation.
 215     void AppendRenderPass(scoped_ptr<RenderPass> render_pass) override;
 216   };
 217
 218   virtual void BeginMainFrameAborted(CommitEarlyOutReason reason);
 219   virtual void BeginCommit();
 220   virtual void CommitComplete();
 221   virtual void Animate(base::TimeTicks monotonic_time);
 222   virtual void UpdateAnimationState(bool start_ready_animations);
 223   void ActivateAnimations();
 224   void MainThreadHasStoppedFlinging();
 225   void DidAnimateScrollOffset();
 226   void SetViewportDamage(const gfx::Rect& damage_rect);
 227
 228   virtual void PrepareTiles();
 229
 230   // Returns DRAW_SUCCESS unless problems occured preparing the frame, and we
 231   // should try to avoid displaying the frame. If PrepareToDraw is called,
 232   // DidDrawAllLayers must also be called, regardless of whether DrawLayers is
 233   // called between the two.
 234   virtual DrawResult PrepareToDraw(FrameData* frame);
 235   virtual void DrawLayers(FrameData* frame, base::TimeTicks frame_begin_time);
 236   // Must be called if and only if PrepareToDraw was called.
 237   void DidDrawAllLayers(const FrameData& frame);
 238
 239   const LayerTreeSettings& settings() const { return settings_; }
 240
 241   // Evict all textures by enforcing a memory policy with an allocation of 0.
 242   void EvictTexturesForTesting();
 243
 244   // When blocking, this prevents client_->NotifyReadyToActivate() from being
 245   // called. When disabled, it calls client_->NotifyReadyToActivate()
 246   // immediately if any notifications had been blocked while blocking.
 247   virtual void BlockNotifyReadyToActivateForTesting(bool block);
 248
 249   // Resets all of the trees to an empty state.
 250   void ResetTreesForTesting();
 251
 252   DrawMode GetDrawMode() const;
 253
 254   // Viewport size in draw space: this size is in physical pixels and is used
 255   // for draw properties, tilings, quads and render passes.
 256   gfx::Size DrawViewportSize() const;
 257
 258   // Viewport rect in view space used for tiling prioritization.
 259   const gfx::Rect ViewportRectForTilePriority() const;
 260
 261   // RendererClient implementation.
 262   void SetFullRootLayerDamage() override;
 263
 264   // TileManagerClient implementation.
 265   void NotifyReadyToActivate() override;
 266   void NotifyReadyToDraw() override;
 267   void NotifyTileStateChanged(const Tile* tile) override;
 268   scoped_ptr<RasterTilePriorityQueue> BuildRasterQueue(
 269       TreePriority tree_priority,
 270       RasterTilePriorityQueue::Type type) override;
 271   scoped_ptr<EvictionTilePriorityQueue> BuildEvictionQueue(
 272       TreePriority tree_priority) override;
 273   void SetIsLikelyToRequireADraw(bool is_likely_to_require_a_draw) override;
 274
 275   // ScrollbarAnimationControllerClient implementation.
 276   void StartAnimatingScrollbarAnimationController(
 277       ScrollbarAnimationController* controller) override;
 278   void StopAnimatingScrollbarAnimationController(
 279       ScrollbarAnimationController* controller) override;
 280   void PostDelayedScrollbarAnimationTask(const base::Closure& task,
 281                                          base::TimeDelta delay) override;
 282   void SetNeedsRedrawForScrollbarAnimation() override;
 283
 284   // VideoBeginFrameSource implementation.
 285   void AddVideoFrameController(VideoFrameController* controller) override;
 286   void RemoveVideoFrameController(VideoFrameController* controller) override;
 287
 288   // OutputSurfaceClient implementation.
 289   void CommitVSyncParameters(base::TimeTicks timebase,
 290                              base::TimeDelta interval) override;
 291   void SetNeedsRedrawRect(const gfx::Rect& rect) override;
 292   void SetExternalDrawConstraints(
 293       const gfx::Transform& transform,
 294       const gfx::Rect& viewport,
 295       const gfx::Rect& clip,
 296       const gfx::Rect& viewport_rect_for_tile_priority,
 297       const gfx::Transform& transform_for_tile_priority,
 298       bool resourceless_software_draw) override;
 299   void DidLoseOutputSurface() override;
 300   void DidSwapBuffers() override;
 301   void DidSwapBuffersComplete() override;
 302   void ReclaimResources(const CompositorFrameAck* ack) override;
 303   void SetMemoryPolicy(const ManagedMemoryPolicy& policy) override;
 304   void SetTreeActivationCallback(const base::Closure& callback) override;
 305   void OnDraw() override;
 306
 307   // Called from LayerTreeImpl.
 308   void OnCanDrawStateChangedForTree();
 309
 310   // Implementation.
 311   int id() const { return id_; }
 312   bool CanDraw() const;
 313   OutputSurface* output_surface() const { return output_surface_.get(); }
 314
 315   std::string LayerTreeAsJson() const;
 316
 317   void FinishAllRendering();
 318   int SourceAnimationFrameNumber() const;
 319
 320   virtual bool InitializeRenderer(scoped_ptr<OutputSurface> output_surface);
 321   TileManager* tile_manager() { return tile_manager_.get(); }
 322   void SetUseGpuRasterization(bool use_gpu);
 323   bool use_gpu_rasterization() const { return use_gpu_rasterization_; }
 324
 325   GpuRasterizationStatus gpu_rasterization_status() const {
 326     return gpu_rasterization_status_;
 327   }
 328   void set_gpu_rasterization_status(
 329       GpuRasterizationStatus gpu_rasterization_status) {
 330     gpu_rasterization_status_ = gpu_rasterization_status;
 331   }
 332
 333   bool create_low_res_tiling() const {
 334     return settings_.create_low_res_tiling && !use_gpu_rasterization_;
 335   }
 336   ResourcePool* resource_pool() { return resource_pool_.get(); }
 337   Renderer* renderer() { return renderer_.get(); }
 338   const RendererCapabilitiesImpl& GetRendererCapabilities() const;
 339
 340   virtual bool SwapBuffers(const FrameData& frame);
 341   virtual void WillBeginImplFrame(const BeginFrameArgs& args);
 342   void DidModifyTilePriorities();
 343
 344   LayerTreeImpl* active_tree() { return active_tree_.get(); }
 345   const LayerTreeImpl* active_tree() const { return active_tree_.get(); }
 346   LayerTreeImpl* pending_tree() { return pending_tree_.get(); }
 347   const LayerTreeImpl* pending_tree() const { return pending_tree_.get(); }
 348   LayerTreeImpl* recycle_tree() { return recycle_tree_.get(); }
 349   const LayerTreeImpl* recycle_tree() const { return recycle_tree_.get(); }
 350   // Returns the tree LTH synchronizes with.
 351   LayerTreeImpl* sync_tree() {
 352     // TODO(enne): This is bogus.  It should return based on the value of
 353     // Proxy::CommitToActiveTree and not whether the pending tree exists.
 354     return pending_tree_ ? pending_tree_.get() : active_tree_.get();
 355   }
 356   virtual void CreatePendingTree();
 357   virtual void ActivateSyncTree();
 358
 359   // Shortcuts to layers on the active tree.
 360   LayerImpl* RootLayer() const;
 361   LayerImpl* InnerViewportScrollLayer() const;
 362   LayerImpl* OuterViewportScrollLayer() const;
 363   LayerImpl* CurrentlyScrollingLayer() const;
 364
 365   int scroll_layer_id_when_mouse_over_scrollbar() const {
 366     return scroll_layer_id_when_mouse_over_scrollbar_;
 367   }
 368   bool scroll_affects_scroll_handler() const {
 369     return scroll_affects_scroll_handler_;
 370   }
 371   void QueueSwapPromiseForMainThreadScrollUpdate(
 372       scoped_ptr<SwapPromise> swap_promise);
 373
 374   bool IsActivelyScrolling() const;
 375
 376   virtual void SetVisible(bool visible);
 377   bool visible() const { return visible_; }
 378
 379   bool AnimationsAreVisible() { return visible() && CanDraw(); }
 380
 381   void SetNeedsCommit() { client_->SetNeedsCommitOnImplThread(); }
 382   void SetNeedsRedraw();
 383
 384   ManagedMemoryPolicy ActualManagedMemoryPolicy() const;
 385
 386   size_t memory_allocation_limit_bytes() const;
 387   int memory_allocation_priority_cutoff() const;
 388
 389   void SetViewportSize(const gfx::Size& device_viewport_size);
 390   gfx::Size device_viewport_size() const { return device_viewport_size_; }
 391
 392   void SetDeviceScaleFactor(float device_scale_factor);
 393   float device_scale_factor() const { return device_scale_factor_; }
 394
 395   void SetPageScaleOnActiveTree(float page_scale_factor);
 396
 397   const gfx::Transform& DrawTransform() const;
 398
 399   scoped_ptr<ScrollAndScaleSet> ProcessScrollDeltas();
 400
 401   void set_max_memory_needed_bytes(size_t bytes) {
 402     max_memory_needed_bytes_ = bytes;
 403   }
 404
 405   FrameRateCounter* fps_counter() {
 406     return fps_counter_.get();
 407   }
 408   PaintTimeCounter* paint_time_counter() {
 409     return paint_time_counter_.get();
 410   }
 411   MemoryHistory* memory_history() {
 412     return memory_history_.get();
 413   }
 414   DebugRectHistory* debug_rect_history() {
 415     return debug_rect_history_.get();
 416   }
 417   ResourceProvider* resource_provider() {
 418     return resource_provider_.get();
 419   }
 420   TopControlsManager* top_controls_manager() {
 421     return top_controls_manager_.get();
 422   }
 423   const GlobalStateThatImpactsTilePriority& global_tile_state() {
 424     return global_tile_state_;
 425   }
 426
 427   Proxy* proxy() const { return proxy_; }
 428
 429   AnimationRegistrar* animation_registrar() const {
 430     return animation_registrar_.get();
 431   }
 432
 433   void SetDebugState(const LayerTreeDebugState& new_debug_state);
 434   const LayerTreeDebugState& debug_state() const { return debug_state_; }
 435
 436   gfx::Vector2dF accumulated_root_overscroll() const {
 437     return accumulated_root_overscroll_;
 438   }
 439
 440   bool pinch_gesture_active() const { return pinch_gesture_active_; }
 441
 442   void SetTreePriority(TreePriority priority);
 443   TreePriority GetTreePriority() const;
 444
 445   void UpdateCurrentBeginFrameArgs(const BeginFrameArgs& args);
 446   void ResetCurrentBeginFrameArgsForNextFrame();
 447   virtual BeginFrameArgs CurrentBeginFrameArgs() const;
 448
 449   // Expected time between two begin impl frame calls.
 450   base::TimeDelta begin_impl_frame_interval() const {
 451     return begin_impl_frame_interval_;
 452   }
 453
 454   void AsValueWithFrameInto(FrameData* frame,
 455                             base::trace_event::TracedValue* value) const;
 456   scoped_refptr<base::trace_event::ConvertableToTraceFormat> AsValueWithFrame(
 457       FrameData* frame) const;
 458   void ActivationStateAsValueInto(base::trace_event::TracedValue* value) const;
 459
 460   bool page_scale_animation_active() const { return !!page_scale_animation_; }
 461
 462   virtual void CreateUIResource(UIResourceId uid,
 463                                 const UIResourceBitmap& bitmap);
 464   // Deletes a UI resource.  May safely be called more than once.
 465   virtual void DeleteUIResource(UIResourceId uid);
 466   void EvictAllUIResources();
 467   bool EvictedUIResourcesExist() const;
 468
 469   virtual ResourceProvider::ResourceId ResourceIdForUIResource(
 470       UIResourceId uid) const;
 471
 472   virtual bool IsUIResourceOpaque(UIResourceId uid) const;
 473
 474   struct UIResourceData {
 475     ResourceProvider::ResourceId resource_id;
 476     gfx::Size size;
 477     bool opaque;
 478   };
 479
 480   void ScheduleMicroBenchmark(scoped_ptr<MicroBenchmarkImpl> benchmark);
 481
 482   CompositorFrameMetadata MakeCompositorFrameMetadata() const;
 483   // Viewport rectangle and clip in nonflipped window space.  These rects
 484   // should only be used by Renderer subclasses to populate glViewport/glClip
 485   // and their software-mode equivalents.
 486   gfx::Rect DeviceViewport() const;
 487   gfx::Rect DeviceClip() const;
 488
 489   // When a SwapPromiseMonitor is created on the impl thread, it calls
 490   // InsertSwapPromiseMonitor() to register itself with LayerTreeHostImpl.
 491   // When the monitor is destroyed, it calls RemoveSwapPromiseMonitor()
 492   // to unregister itself.
 493   void InsertSwapPromiseMonitor(SwapPromiseMonitor* monitor);
 494   void RemoveSwapPromiseMonitor(SwapPromiseMonitor* monitor);
 495
 496   void GetPictureLayerImplPairs(std::vector<PictureLayerImpl::Pair>* layers,
 497                                 bool need_valid_tile_priorities) const;
 498
 499   // TODO(weiliangc): Replace RequiresHighResToDraw with scheduler waits for
 500   // ReadyToDraw. crbug.com/469175
 501   void SetRequiresHighResToDraw() { requires_high_res_to_draw_ = true; }
 502   void ResetRequiresHighResToDraw() { requires_high_res_to_draw_ = false; }
 503   bool RequiresHighResToDraw() const { return requires_high_res_to_draw_; }
 504
 505   // Only valid for synchronous (non-scheduled) single-threaded case.
 506   void SynchronouslyInitializeAllTiles();
 507
 508   virtual void CreateResourceAndTileTaskWorkerPool(
 509       scoped_ptr<TileTaskWorkerPool>* tile_task_worker_pool,
 510       scoped_ptr<ResourcePool>* resource_pool,
 511       scoped_ptr<ResourcePool>* staging_resource_pool);
 512
 513   bool prepare_tiles_needed() const { return tile_priorities_dirty_; }
 514
 515   FrameTimingTracker* frame_timing_tracker() {
 516     return frame_timing_tracker_.get();
 517   }
 518
 519   gfx::Vector2dF ScrollLayer(LayerImpl* layer_impl,
 520                              const gfx::Vector2dF& delta,
 521                              const gfx::Point& viewport_point,
 522                              bool is_wheel_scroll);
 523
 524   // Record main frame timing information.
 525   // |start_of_main_frame_args| is the BeginFrameArgs of the beginning of the
 526   // main frame (ie the frame that kicked off the main frame).
 527   // |expected_next_main_frame_args| is the BeginFrameArgs of the frame that
 528   // follows the completion of the main frame (whether it is activation or some
 529   // other completion, such as early out). Note that if there is a main frame
 530   // scheduled in that frame, then this BeginFrameArgs will become the main
 531   // frame args. However, if no such frame is scheduled, then this _would_ be
 532   // the main frame args if it was scheduled.
 533   void RecordMainFrameTiming(
 534       const BeginFrameArgs& start_of_main_frame_args,
 535       const BeginFrameArgs& expected_next_main_frame_args);
 536
 537  protected:
 538   LayerTreeHostImpl(
 539       const LayerTreeSettings& settings,
 540       LayerTreeHostImplClient* client,
 541       Proxy* proxy,
 542       RenderingStatsInstrumentation* rendering_stats_instrumentation,
 543       SharedBitmapManager* shared_bitmap_manager,
 544       gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
 545       TaskGraphRunner* task_graph_runner,
 546       int id);
 547
 548   // Virtual for testing.
 549   virtual void AnimateLayers(base::TimeTicks monotonic_time);
 550
 551   bool is_likely_to_require_a_draw() const {
 552     return is_likely_to_require_a_draw_;
 553   }
 554
 555   // Removes empty or orphan RenderPasses from the frame.
 556   static void RemoveRenderPasses(FrameData* frame);
 557
 558   LayerTreeHostImplClient* client_;
 559   Proxy* proxy_;
 560
 561  private:
 562   gfx::Vector2dF ScrollLayerWithViewportSpaceDelta(
 563       LayerImpl* layer_impl,
 564       const gfx::PointF& viewport_point,
 565       const gfx::Vector2dF& viewport_delta);
 566
 567   void CreateAndSetRenderer();
 568   void CreateAndSetTileManager();
 569   void DestroyTileManager();
 570   void ReleaseTreeResources();
 571   void RecreateTreeResources();
 572
 573   bool IsSynchronousSingleThreaded() const;
 574
 575   Viewport* viewport() { return viewport_.get(); }
 576
 577   // Scroll by preferring to move the outer viewport first, only moving the
 578   // inner if the outer is at its scroll extents.
 579   void ScrollViewportBy(gfx::Vector2dF scroll_delta);
 580   // Scroll by preferring to move the inner viewport first, only moving the
 581   // outer if the inner is at its scroll extents.
 582   void ScrollViewportInnerFirst(gfx::Vector2dF scroll_delta);
 583
 584   void AnimatePageScale(base::TimeTicks monotonic_time);
 585   void AnimateScrollbars(base::TimeTicks monotonic_time);
 586   void AnimateTopControls(base::TimeTicks monotonic_time);
 587
 588   void TrackDamageForAllSurfaces(
 589       LayerImpl* root_draw_layer,
 590       const LayerImplList& render_surface_layer_list);
 591
 592   void UpdateTileManagerMemoryPolicy(const ManagedMemoryPolicy& policy);
 593
 594   // This function should only be called from PrepareToDraw, as DidDrawAllLayers
 595   // must be called if this helper function is called.  Returns DRAW_SUCCESS if
 596   // the frame should be drawn.
 597   DrawResult CalculateRenderPasses(FrameData* frame);
 598
 599   void ClearCurrentlyScrollingLayer();
 600
 601   bool HandleMouseOverScrollbar(LayerImpl* layer_impl,
 602                                 const gfx::PointF& device_viewport_point);
 603
 604   LayerImpl* FindScrollLayerForDeviceViewportPoint(
 605       const gfx::PointF& device_viewport_point,
 606       InputHandler::ScrollInputType type,
 607       LayerImpl* layer_hit_by_point,
 608       bool* scroll_on_main_thread,
 609       bool* optional_has_ancestor_scroll_handler) const;
 610   float DeviceSpaceDistanceToLayer(const gfx::PointF& device_viewport_point,
 611                                    LayerImpl* layer_impl);
 612   void StartScrollbarFadeRecursive(LayerImpl* layer);
 613   void SetManagedMemoryPolicy(const ManagedMemoryPolicy& policy);
 614   void EnforceManagedMemoryPolicy(const ManagedMemoryPolicy& policy);
 615
 616   void MarkUIResourceNotEvicted(UIResourceId uid);
 617
 618   void NotifySwapPromiseMonitorsOfSetNeedsRedraw();
 619   void NotifySwapPromiseMonitorsOfForwardingToMainThread();
 620
 621   void ScrollAnimationCreate(LayerImpl* layer_impl,
 622                              const gfx::ScrollOffset& target_offset,
 623                              const gfx::ScrollOffset& current_offset);
 624   bool ScrollAnimationUpdateTarget(LayerImpl* layer_impl,
 625                                    const gfx::Vector2dF& scroll_delta);
 626
 627   typedef base::hash_map<UIResourceId, UIResourceData>
 628       UIResourceMap;
 629   UIResourceMap ui_resource_map_;
 630
 631   // Resources that were evicted by EvictAllUIResources. Resources are removed
 632   // from this when they are touched by a create or destroy from the UI resource
 633   // request queue.
 634   std::set<UIResourceId> evicted_ui_resources_;
 635
 636   scoped_ptr<OutputSurface> output_surface_;
 637
 638   // |resource_provider_| and |tile_manager_| can be NULL, e.g. when using tile-
 639   // free rendering - see OutputSurface::ForcedDrawToSoftwareDevice().
 640   // |tile_manager_| can also be NULL when raster_enabled is false.
 641   scoped_ptr<ResourceProvider> resource_provider_;
 642   scoped_ptr<TileManager> tile_manager_;
 643   bool use_gpu_rasterization_;
 644   GpuRasterizationStatus gpu_rasterization_status_;
 645   scoped_ptr<TileTaskWorkerPool> tile_task_worker_pool_;
 646   scoped_ptr<ResourcePool> resource_pool_;
 647   scoped_ptr<ResourcePool> staging_resource_pool_;
 648   scoped_ptr<Renderer> renderer_;
 649
 650   GlobalStateThatImpactsTilePriority global_tile_state_;
 651
 652   // Tree currently being drawn.
 653   scoped_ptr<LayerTreeImpl> active_tree_;
 654
 655   // In impl-side painting mode, tree with possibly incomplete rasterized
 656   // content. May be promoted to active by ActivatePendingTree().
 657   scoped_ptr<LayerTreeImpl> pending_tree_;
 658
 659   // In impl-side painting mode, inert tree with layers that can be recycled
 660   // by the next sync from the main thread.
 661   scoped_ptr<LayerTreeImpl> recycle_tree_;
 662
 663   InputHandlerClient* input_handler_client_;
 664   bool did_lock_scrolling_layer_;
 665   bool should_bubble_scrolls_;
 666   bool wheel_scrolling_;
 667   bool scroll_affects_scroll_handler_;
 668   int scroll_layer_id_when_mouse_over_scrollbar_;
 669   ScopedPtrVector<SwapPromise> swap_promises_for_main_thread_scroll_update_;
 670
 671   // An object to implement the ScrollElasticityHelper interface and
 672   // hold all state related to elasticity. May be NULL if never requested.
 673   scoped_ptr<ScrollElasticityHelper> scroll_elasticity_helper_;
 674
 675   bool tile_priorities_dirty_;
 676
 677   // The optional delegate for the root layer scroll offset.
 678   LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate_;
 679   LayerTreeSettings settings_;
 680   LayerTreeDebugState debug_state_;
 681   bool visible_;
 682   ManagedMemoryPolicy cached_managed_memory_policy_;
 683
 684   gfx::Vector2dF accumulated_root_overscroll_;
 685
 686   bool pinch_gesture_active_;
 687   bool pinch_gesture_end_should_clear_scrolling_layer_;
 688   gfx::Point previous_pinch_anchor_;
 689
 690   scoped_ptr<TopControlsManager> top_controls_manager_;
 691
 692   scoped_ptr<PageScaleAnimation> page_scale_animation_;
 693
 694   scoped_ptr<FrameRateCounter> fps_counter_;
 695   scoped_ptr<PaintTimeCounter> paint_time_counter_;
 696   scoped_ptr<MemoryHistory> memory_history_;
 697   scoped_ptr<DebugRectHistory> debug_rect_history_;
 698
 699   scoped_ptr<TextureMailboxDeleter> texture_mailbox_deleter_;
 700
 701   // The maximum memory that would be used by the prioritized resource
 702   // manager, if there were no limit on memory usage.
 703   size_t max_memory_needed_bytes_;
 704
 705   // Viewport size passed in from the main thread, in physical pixels.  This
 706   // value is the default size for all concepts of physical viewport (draw
 707   // viewport, scrolling viewport and device viewport), but it can be
 708   // overridden.
 709   gfx::Size device_viewport_size_;
 710
 711   // Conversion factor from CSS pixels to physical pixels when
 712   // pageScaleFactor=1.
 713   float device_scale_factor_;
 714
 715   // Optional top-level constraints that can be set by the OutputSurface.
 716   // - external_transform_ applies a transform above the root layer
 717   // - external_viewport_ is used DrawProperties, tile management and
 718   // glViewport/window projection matrix.
 719   // - external_clip_ specifies a top-level clip rect
 720   // - viewport_rect_for_tile_priority_ is the rect in view space used for
 721   // tiling priority.
 722   gfx::Transform external_transform_;
 723   gfx::Rect external_viewport_;
 724   gfx::Rect external_clip_;
 725   gfx::Rect viewport_rect_for_tile_priority_;
 726   bool resourceless_software_draw_;
 727
 728   gfx::Rect viewport_damage_rect_;
 729
 730   BeginFrameArgs current_begin_frame_args_;
 731
 732   // Expected time between two begin impl frame calls.
 733   base::TimeDelta begin_impl_frame_interval_;
 734
 735   scoped_ptr<AnimationRegistrar> animation_registrar_;
 736   std::set<ScrollbarAnimationController*> scrollbar_animation_controllers_;
 737   std::set<VideoFrameController*> video_frame_controllers_;
 738
 739   RenderingStatsInstrumentation* rendering_stats_instrumentation_;
 740   MicroBenchmarkControllerImpl micro_benchmark_controller_;
 741   scoped_ptr<TaskGraphRunner> single_thread_synchronous_task_graph_runner_;
 742
 743   // Optional callback to notify of new tree activations.
 744   base::Closure tree_activation_callback_;
 745
 746   SharedBitmapManager* shared_bitmap_manager_;
 747   gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager_;
 748   TaskGraphRunner* task_graph_runner_;
 749   int id_;
 750
 751   std::set<SwapPromiseMonitor*> swap_promise_monitor_;
 752   std::vector<PictureLayerImpl::Pair> picture_layer_pairs_;
 753
 754   bool requires_high_res_to_draw_;
 755   bool is_likely_to_require_a_draw_;
 756
 757   scoped_ptr<FrameTimingTracker> frame_timing_tracker_;
 758
 759   scoped_ptr<Viewport> viewport_;
 760
 761   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 762 };
 763
 764 }  // namespace cc
 765
 766 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_