Only send the FrameSinkId to client when it is necessary

services/ui/public/cpp/client_compositor_frame_sink.h

 // Copyright 2014 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 SERVICES_UI_PUBLIC_CPP_WINDOW_COMPOSITOR_FRAME_SINK_H_
 #define SERVICES_UI_PUBLIC_CPP_WINDOW_COMPOSITOR_FRAME_SINK_H_
 
 #include "base/macros.h"
 #include "cc/ipc/mojo_compositor_frame_sink.mojom.h"
 #include "cc/output/compositor_frame_sink.h"
 #include "cc/output/context_provider.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/surfaces/local_surface_id_allocator.h"
 #include "cc/surfaces/surface_id.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace ui {
 
 class ClientCompositorFrameSinkBinding;
 
 class ClientCompositorFrameSink
     : public cc::CompositorFrameSink,
       public cc::mojom::MojoCompositorFrameSinkClient,
       public cc::ExternalBeginFrameSourceClient {
  public:
   // static
   static std::unique_ptr<ClientCompositorFrameSink> Create(
-      const cc::FrameSinkId& frame_sink_id,
       scoped_refptr<cc::ContextProvider> context_provider,
       gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
       std::unique_ptr<ClientCompositorFrameSinkBinding>*
-          compositor_frame_sink_binding);
+          compositor_frame_sink_binding,
+      bool enable_surface_synchronization);
 
   ~ClientCompositorFrameSink() override;
 
   // cc::CompositorFrameSink implementation.
   bool BindToClient(cc::CompositorFrameSinkClient* client) override;
   void DetachFromClient() override;
   void SetLocalSurfaceId(const cc::LocalSurfaceId& local_surface_id) override;
   void SubmitCompositorFrame(cc::CompositorFrame frame) override;
 
  private:
   ClientCompositorFrameSink(
-      const cc::FrameSinkId& frame_sink_id,
       scoped_refptr<cc::ContextProvider> context_provider,
       gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
       cc::mojom::MojoCompositorFrameSinkPtrInfo compositor_frame_sink_info,
-      cc::mojom::MojoCompositorFrameSinkClientRequest client_request);
+      cc::mojom::MojoCompositorFrameSinkClientRequest client_request,
+      bool enable_surface_synchronization);
 
   // cc::mojom::MojoCompositorFrameSinkClient implementation:
   void DidReceiveCompositorFrameAck(
       const cc::ReturnedResourceArray& resources) override;
   void OnBeginFrame(const cc::BeginFrameArgs& begin_frame_args) override;
   void ReclaimResources(const cc::ReturnedResourceArray& resources) override;
 
   // cc::ExternalBeginFrameSourceClient implementation.
   void OnNeedsBeginFrames(bool needs_begin_frames) override;
   void OnDidFinishFrame(const cc::BeginFrameAck& ack) override;
 
   gfx::Size last_submitted_frame_size_;
   cc::LocalSurfaceId local_surface_id_;
   cc::LocalSurfaceIdAllocator id_allocator_;
   std::unique_ptr<cc::ExternalBeginFrameSource> begin_frame_source_;
   cc::mojom::MojoCompositorFrameSinkPtrInfo compositor_frame_sink_info_;
   cc::mojom::MojoCompositorFrameSinkClientRequest client_request_;
   cc::mojom::MojoCompositorFrameSinkPtr compositor_frame_sink_;
   std::unique_ptr<mojo::Binding<cc::mojom::MojoCompositorFrameSinkClient>>
       client_binding_;
   std::unique_ptr<base::ThreadChecker> thread_checker_;
-  const cc::FrameSinkId frame_sink_id_;
-  bool enable_surface_synchronization_ = false;
+  const bool enable_surface_synchronization_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientCompositorFrameSink);
 };
 
 // A ClientCompositorFrameSinkBinding is a bundle of mojo interfaces that is
 // created by ClientCompositorFrameSink::Create and is used by or implemented by
 // Mus when a window is attached to a frame-sink..
 // ClientCompositorFrameSinkBinding has no standalone functionality. Its purpose
 // is to allow safely creating and attaching a CompositorFrameSink on one
 // thread and using it on another.
@@ skipping 13 matching lines @@
           compositor_frame_sink_client);
 
   cc::mojom::MojoCompositorFrameSinkRequest compositor_frame_sink_request_;
   cc::mojom::MojoCompositorFrameSinkClientPtrInfo compositor_frame_sink_client_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientCompositorFrameSinkBinding);
 };
 }  // namespace ui
 
 #endif  // SERVICES_UI_PUBLIC_CPP_WINDOW_COMPOSITOR_FRAME_SINK_H_