WIP: Propagate SurfaceID up window tree hierarchy

ui/views/mus/surface_context_factory.h

 // Copyright 2015 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 UI_VIEWS_MUS_SURFACE_CONTEXT_FACTORY_H_
 #define UI_VIEWS_MUS_SURFACE_CONTEXT_FACTORY_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
@@ skipping 23 matching lines @@
       ui::Layer* mirroring_layer) override;
   void RemoveReflector(ui::Reflector* reflector) override;
   scoped_refptr<cc::ContextProvider> SharedMainThreadContextProvider() override;
   void RemoveCompositor(ui::Compositor* compositor) override;
   bool DoesCreateTestContexts() override;
   uint32_t GetImageTextureTarget(gfx::BufferFormat format,
                                  gfx::BufferUsage usage) override;
   cc::SharedBitmapManager* GetSharedBitmapManager() override;
   gpu::GpuMemoryBufferManager* GetGpuMemoryBufferManager() override;
   cc::TaskGraphRunner* GetTaskGraphRunner() override;
-  uint32_t AllocateSurfaceClientId() override;
+  cc::FrameSinkId AllocateFrameSinkId() override;
   cc::SurfaceManager* GetSurfaceManager() override;
   void SetDisplayVisible(ui::Compositor* compositor, bool visible) override;
   void ResizeDisplay(ui::Compositor* compositor,
                      const gfx::Size& size) override;
   void SetDisplayColorSpace(ui::Compositor* compositor,
                             const gfx::ColorSpace& color_space) override {}
   void SetAuthoritativeVSyncInterval(ui::Compositor* compositor,
                                      base::TimeDelta interval) override {}
   void SetDisplayVSyncParameters(ui::Compositor* compositor,
                                  base::TimeTicks timebase,
                                  base::TimeDelta interval) override {}
   void SetOutputIsSecure(ui::Compositor* compositor, bool secure) override {}
   void AddObserver(ui::ContextFactoryObserver* observer) override {}
   void RemoveObserver(ui::ContextFactoryObserver* observer) override {}
 
   cc::SurfaceManager surface_manager_;
   uint32_t next_surface_id_namespace_;
   ui::RasterThreadHelper raster_thread_helper_;
   ui::GpuService* gpu_service_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfaceContextFactory);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_MUS_SURFACE_CONTEXT_FACTORY_H_