Reduce SurfaceIdAllocator usage and tie SurfaceFactory to a single FrameSinkId

components/exo/surface.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 COMPONENTS_EXO_SURFACE_H_
 #define COMPONENTS_EXO_SURFACE_H_
 
 #include <list>
 #include <memory>
 #include <set>
@@ skipping 63 matching lines @@
  private:
   friend class base::RefCounted<SurfaceFactoryOwner>;
   friend class Surface;
 
   ~SurfaceFactoryOwner() override;
 
   std::map<int,
            std::pair<scoped_refptr<SurfaceFactoryOwner>,
                      std::unique_ptr<cc::SingleReleaseCallback>>>
       release_callbacks_;
+  cc::FrameSinkId frame_sink_id_;
   std::unique_ptr<cc::SurfaceIdAllocator> id_allocator_;
   std::unique_ptr<cc::SurfaceFactory> surface_factory_;
   Surface* surface_ = nullptr;
 };
 
 // This class represents a rectangular area that is displayed on the screen.
 // It has a location, size and pixel contents.
 class Surface : public ui::LayerOwnerDelegate,
                 public ui::ContextFactoryObserver {
  public:
@@ skipping 305 matching lines @@
 
   // Surface observer list. Surface does not own the observers.
   base::ObserverList<SurfaceObserver, true> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(Surface);
 };
 
 }  // namespace exo
 
 #endif  // COMPONENTS_EXO_SURFACE_H_