Decouple GpuCompositorFrameSink from DisplayCompositor

services/ui/surfaces/display_compositor.h

Index: services/ui/surfaces/display_compositor.h
diff --git a/services/ui/surfaces/display_compositor.h b/services/ui/surfaces/display_compositor.h
index 8616b1e40d08a057c4ac83a0752826fd064ea342..938cfb0ac706461af83b548eb06f982703aca11a 100644
--- a/services/ui/surfaces/display_compositor.h
+++ b/services/ui/surfaces/display_compositor.h
@@ -19,6 +19,7 @@
 #include "cc/surfaces/surface_id.h"
 #include "cc/surfaces/surface_manager.h"
 #include "cc/surfaces/surface_observer.h"
+#include "components/display_compositor/gpu_compositor_frame_sink_delegate.h"
 #include "gpu/command_buffer/client/gpu_memory_buffer_manager.h"
 #include "gpu/ipc/common/surface_handle.h"
 #include "gpu/ipc/in_process_command_buffer.h"
@@ -36,17 +37,21 @@ class SurfaceManager;
 class SyntheticBeginFrameSource;
 }
 
-namespace ui {
-
+namespace display_compositor {
 class GpuCompositorFrameSink;
+}
+
+namespace ui {
 
 // The DisplayCompositor object is an object global to the Window Server app
 // that holds the SurfaceServer and allocates new Surfaces namespaces.
 // This object lives on the main thread of the Window Server.
 // TODO(rjkroege, fsamuel): This object will need to change to support multiple
 // displays.
-class DisplayCompositor : public cc::SurfaceObserver,
-                          public cc::mojom::DisplayCompositor {
+class DisplayCompositor
+    : public cc::SurfaceObserver,
+      public display_compositor::GpuCompositorFrameSinkDelegate,
+      public cc::mojom::DisplayCompositor {
  public:
   DisplayCompositor(
       scoped_refptr<gpu::InProcessCommandBuffer::Service> gpu_service,
@@ -58,24 +63,11 @@ class DisplayCompositor : public cc::SurfaceObserver,
 
   cc::SurfaceManager* manager() { return &manager_; }
 
-  // Adds surface references. For each reference added, this will remove the
-  // temporary reference to the child surface if one exists.
-  void AddSurfaceReferences(
-      const std::vector<cc::SurfaceReference>& references);
-
-  // Removes surface references.
-  void RemoveSurfaceReferences(
-      const std::vector<cc::SurfaceReference>& references);
-
-  // We must avoid destroying a GpuCompositorFrameSink until both the display
-  // compositor host and the client drop their connection to avoid getting into
-  // a state where surfaces references are inconsistent.
-  void OnCompositorFrameSinkClientConnectionLost(
-      const cc::FrameSinkId& frame_sink_id,
-      bool destroy_compositor_frame_sink);
-  void OnCompositorFrameSinkPrivateConnectionLost(
-      const cc::FrameSinkId& frame_sink_id,
-      bool destroy_compositor_frame_sink);
+  // display_compositor::GpuCompositorFrameSinkDelegate implementation.
+  void OnClientConnectionLost(const cc::FrameSinkId& frame_sink_id,
+                              bool destroy_compositor_frame_sink) override;
+  void OnPrivateConnectionLost(const cc::FrameSinkId& frame_sink_id,
+                               bool destroy_compositor_frame_sink) override;
 
   // cc::mojom::DisplayCompositor implementation:
   void CreateDisplayCompositorFrameSink(
@@ -128,9 +120,10 @@ class DisplayCompositor : public cc::SurfaceObserver,
   std::unique_ptr<gpu::GpuMemoryBufferManager> gpu_memory_buffer_manager_;
   gpu::ImageFactory* image_factory_;
 
-  std::unordered_map<cc::FrameSinkId,
-                     std::unique_ptr<GpuCompositorFrameSink>,
-                     cc::FrameSinkIdHash>
+  std::unordered_map<
+      cc::FrameSinkId,
+      std::unique_ptr<display_compositor::GpuCompositorFrameSink>,
+      cc::FrameSinkIdHash>
       compositor_frame_sinks_;
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;