DirectCompositorFrameSink Uses CompositorFrameSinkSupport

cc/surfaces/compositor_frame_sink_support.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_SURFACES_COMPOSITOR_FRAME_SINK_SUPPORT_H_
 #define CC_SURFACES_COMPOSITOR_FRAME_SINK_SUPPORT_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/surfaces/display.h"
 #include "cc/surfaces/display_client.h"
 #include "cc/surfaces/surface_factory.h"
 #include "cc/surfaces/surface_factory_client.h"
 #include "cc/surfaces/surfaces_export.h"
 
 namespace cc {
 
 class CompositorFrameSinkSupportClient;
 class Display;
 class SurfaceManager;
 
 class CC_SURFACES_EXPORT CompositorFrameSinkSupport
     : public NON_EXPORTED_BASE(DisplayClient),
       public SurfaceFactoryClient,
       public BeginFrameObserver {
  public:
-  CompositorFrameSinkSupport(
-      CompositorFrameSinkSupportClient* client,
-      SurfaceManager* surface_manager,
-      const FrameSinkId& frame_sink_id,
-      std::unique_ptr<Display> display,
-      std::unique_ptr<BeginFrameSource> display_begin_frame_source);
+  // |display| is nullptr if the CompositorFrameSinkSupport submits
+  // CompositorFrames to a offscreen texutre/bitmap instead of a
+  // DisplayCompositor. e.g. OffscreenCanvasCompositorFrameSink and
+  // GpuOffscreenCompositorFrameSink.
+  CompositorFrameSinkSupport(CompositorFrameSinkSupportClient* client,
+                             SurfaceManager* surface_manager,
+                             const FrameSinkId& frame_sink_id,
+                             Display* display,
+                             bool needs_sync_points = true,

[danakj, 2017/02/06 16:42:58]

Why do these have default values instead of writing the wishes of each caller
explicitly?

[Alex Z., 2017/02/07 17:22:00]

Done.

+                             bool for_direct_compositor_frame_sink = false);
 
   ~CompositorFrameSinkSupport() override;
 
   const FrameSinkId& frame_sink_id() const { return frame_sink_id_; }
 
   void EvictFrame();
   void SetNeedsBeginFrame(bool needs_begin_frame);
   void SubmitCompositorFrame(const LocalSurfaceId& local_surface_id,
                              CompositorFrame frame);
   void Require(const LocalSurfaceId& local_surface_id,
                const SurfaceSequence& sequence);
   void Satisfy(const SurfaceSequence& sequence);
   void AddChildFrameSink(const FrameSinkId& child_frame_sink_id);
   void RemoveChildFrameSink(const FrameSinkId& child_frame_sink_id);
+  void ForceReclaimResources();
 
-  Display* display() { return display_.get(); }
+  Display* display() { return display_; }
 
  private:
   void DidReceiveCompositorFrameAck();
 
   // DisplayClient implementation.
   void DisplayOutputSurfaceLost() override;
   void DisplayWillDrawAndSwap(bool will_draw_and_swap,
                               const RenderPassList& render_passes) override;
   void DisplayDidDrawAndSwap() override;
 
   // SurfaceFactoryClient implementation.
   void ReturnResources(const ReturnedResourceArray& resources) override;
   void SetBeginFrameSource(BeginFrameSource* begin_frame_source) override;
   void WillDrawSurface(const LocalSurfaceId& local_surface_id,
                        const gfx::Rect& damage_rect) override;
 
   // BeginFrameObserver implementation.
   void OnBeginFrame(const BeginFrameArgs& args) override;
   const BeginFrameArgs& LastUsedBeginFrameArgs() const override;
   void OnBeginFrameSourcePausedChanged(bool paused) override;
 
   void UpdateNeedsBeginFramesInternal();
 
   CompositorFrameSinkSupportClient* const client_;
 
   SurfaceManager* const surface_manager_;
-
   const FrameSinkId frame_sink_id_;
-
-  // GpuCompositorFrameSink holds a Display and its BeginFrameSource if it
-  // created with non-null gpu::SurfaceHandle. In the window server, the display
-  // root window's CompositorFrameSink will have a valid gpu::SurfaceHandle.
-  std::unique_ptr<BeginFrameSource> display_begin_frame_source_;
-  std::unique_ptr<Display> display_;
+  Display* const display_;
 
   SurfaceFactory surface_factory_;
   // Counts the number of CompositorFrames that have been submitted and have not
   // yet received an ACK.
   int ack_pending_count_ = 0;
   ReturnedResourceArray surface_returned_resources_;
 
   // The begin frame source being observered. Null if none.
   BeginFrameSource* begin_frame_source_ = nullptr;
 
   // The last begin frame args generated by the begin frame source.
   BeginFrameArgs last_begin_frame_args_;
 
   // Whether a request for begin frames has been issued.
   bool needs_begin_frame_ = false;
 
   // Whether or not a frame observer has been added.
   bool added_frame_observer_ = false;
 
+  // TODO(staraz): Remove this flag once ui::Compositor no longer needs
+  // RegisterFrameSinkId().
+  bool for_direct_compositor_frame_sink_;

[danakj, 2017/02/06 16:42:58]

const?

[Alex Z., 2017/02/07 17:22:00]

Done.

+
   // The set of BeginFrame children of this CompositorFrameSink.
   std::unordered_set<FrameSinkId, FrameSinkIdHash> child_frame_sinks_;
 
   base::WeakPtrFactory<CompositorFrameSinkSupport> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CompositorFrameSinkSupport);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_COMPOSITOR_FRAME_SINK_SUPPORT_H_