Only send the FrameSinkId to client when it is necessary

content/renderer/mus/renderer_window_tree_client.h

 // Copyright 2017 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 CONTENT_RENDERER_MUS_RENDERER_WINDOW_TREE_CLIENT_H_
 #define CONTENT_RENDERER_MUS_RENDERER_WINDOW_TREE_CLIENT_H_
 
 #include "base/macros.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "services/ui/common/types.h"
@@ skipping 53 matching lines @@
   // these will remain unimplemented in the long-term. Some of the
   // implementations would require some amount of refactoring out of
   // RenderWidget and related classes (e.g. resize, input, ime etc.).
   void OnEmbed(
       ui::ClientSpecificId client_id,
       ui::mojom::WindowDataPtr root,
       ui::mojom::WindowTreePtr tree,
       int64_t display_id,
       ui::Id focused_window_id,
       bool drawn,
-      const cc::FrameSinkId& frame_sink_id,
       const base::Optional<cc::LocalSurfaceId>& local_surface_id) override;
   void OnEmbeddedAppDisconnected(ui::Id window_id) override;
   void OnUnembed(ui::Id window_id) override;
   void OnCaptureChanged(ui::Id new_capture_window_id,
                         ui::Id old_capture_window_id) override;
   void OnFrameSinkIdAllocated(ui::Id window_id,
                               const cc::FrameSinkId& frame_sink_id) override;
   void OnTopLevelCreated(
       uint32_t change_id,
       ui::mojom::WindowDataPtr data,
       int64_t display_id,
       bool drawn,
-      const cc::FrameSinkId& frame_sink_id,
       const base::Optional<cc::LocalSurfaceId>& local_surface_id) override;
   void OnWindowBoundsChanged(
       ui::Id window_id,
       const gfx::Rect& old_bounds,
       const gfx::Rect& new_bounds,
       const base::Optional<cc::LocalSurfaceId>& local_frame_id) override;
   void OnClientAreaChanged(
       uint32_t window_id,
       const gfx::Insets& new_client_area,
       const std::vector<gfx::Rect>& new_additional_client_areas) override;
@@ skipping 55 matching lines @@
                                   uint32_t action_taken) override;
   void OnDragDropDone() override;
   void OnChangeCompleted(uint32_t change_id, bool success) override;
   void RequestClose(uint32_t window_id) override;
   void GetWindowManager(
       mojo::AssociatedInterfaceRequest<ui::mojom::WindowManager> internal)
       override;
 
   const int routing_id_;
   ui::Id root_window_id_;
-  cc::FrameSinkId frame_sink_id_;
   scoped_refptr<cc::ContextProvider> pending_context_provider_;
   gpu::GpuMemoryBufferManager* pending_gpu_memory_buffer_manager_ = nullptr;
   CompositorFrameSinkCallback pending_compositor_frame_sink_callback_;
   ui::mojom::WindowTreePtr tree_;
   mojo::Binding<ui::mojom::WindowTreeClient> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererWindowTreeClient);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MUS_RENDERER_WINDOW_TREE_CLIENT_H_