Introduce FrameSinkManagerHost in content/browser/.

content/browser/compositor/gpu_process_transport_factory.h

Index: content/browser/compositor/gpu_process_transport_factory.h
diff --git a/content/browser/compositor/gpu_process_transport_factory.h b/content/browser/compositor/gpu_process_transport_factory.h
index cab105ae0fde582a57c0933fb4bad4ad358912bc..a07fae2de36b84136c6d9ff34191d162f4f7b6a4 100644
--- a/content/browser/compositor/gpu_process_transport_factory.h
+++ b/content/browser/compositor/gpu_process_transport_factory.h
@@ -34,6 +34,7 @@ class ContextProviderCommandBuffer;
 
 namespace content {
 class OutputDeviceBacking;
+class FrameSinkManagerHost;
 
 class GpuProcessTransportFactory : public ui::ContextFactory,
                                    public ui::ContextFactoryPrivate,
@@ -78,6 +79,7 @@ class GpuProcessTransportFactory : public ui::ContextFactory,
   ui::ContextFactory* GetContextFactory() override;
   ui::ContextFactoryPrivate* GetContextFactoryPrivate() override;
   cc::SurfaceManager* GetSurfaceManager() override;
+  FrameSinkManagerHost* GetFrameSinkManagerHost() override;
   display_compositor::GLHelper* GetGLHelper() override;
   void SetGpuChannelEstablishFactory(
       gpu::GpuChannelEstablishFactory* factory) override;
@@ -104,7 +106,9 @@ class GpuProcessTransportFactory : public ui::ContextFactory,
   scoped_refptr<cc::VulkanInProcessContextProvider>
   SharedVulkanContextProvider();
 
-  std::unique_ptr<cc::SurfaceManager> surface_manager_;
+  // Manages creation and hierarchy of frame sinks.
+  std::unique_ptr<FrameSinkManagerHost> frame_sink_manager_host_;
+
   cc::FrameSinkIdAllocator frame_sink_id_allocator_;
 
 #if defined(OS_WIN)