Introduce separate client and init path for single-threaded cc

ui/compositor/compositor.h

 // Copyright (c) 2012 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_COMPOSITOR_COMPOSITOR_H_
 #define UI_COMPOSITOR_COMPOSITOR_H_
 
 #include <string>
 
 #include "base/containers/hash_tables.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
 #include "cc/trees/layer_tree_host_client.h"
+#include "cc/trees/layer_tree_host_single_thread_client.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/compositor/compositor_export.h"
 #include "ui/compositor/compositor_observer.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/size.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/vector2d.h"
 #include "ui/gl/gl_share_group.h"
 
 class SkBitmap;
@@ skipping 186 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(DrawWaiterForTest);
 };
 
 // Compositor object to take care of GPU painting.
 // A Browser compositor object is responsible for generating the final
 // displayable form of pixels comprising a single widget's contents. It draws an
 // appropriately transformed texture for each transformed view in the widget's
 // view hierarchy.
 class COMPOSITOR_EXPORT Compositor
     : NON_EXPORTED_BASE(public cc::LayerTreeHostClient),
+      NON_EXPORTED_BASE(public cc::LayerTreeHostSingleThreadClient),
       public base::SupportsWeakPtr<Compositor> {
  public:
   explicit Compositor(gfx::AcceleratedWidget widget);
   virtual ~Compositor();
 
   static void Initialize();
   static bool WasInitializedWithThread();
   static scoped_refptr<base::MessageLoopProxy> GetCompositorMessageLoop();
   static void Terminate();
 
@@ skipping 82 matching lines @@
   virtual void Layout() OVERRIDE;
   virtual void ApplyScrollAndScale(gfx::Vector2d scroll_delta,
                                    float page_scale) OVERRIDE {}
   virtual scoped_ptr<cc::OutputSurface> CreateOutputSurface(bool fallback)
       OVERRIDE;
   virtual void DidInitializeOutputSurface(bool success) OVERRIDE {}
   virtual void WillCommit() OVERRIDE {}
   virtual void DidCommit() OVERRIDE;
   virtual void DidCommitAndDrawFrame() OVERRIDE;
   virtual void DidCompleteSwapBuffers() OVERRIDE;
-  virtual void ScheduleComposite() OVERRIDE;
   virtual scoped_refptr<cc::ContextProvider>
       OffscreenContextProvider() OVERRIDE;
 
+  // cc::LayerTreeHostSingleThreadClient implementation.
+  virtual void ScheduleComposite() OVERRIDE;
+  virtual void DidPostSwapBuffers() OVERRIDE {}
+  virtual void DidAbortSwapBuffers() OVERRIDE {}
+
   int last_started_frame() { return last_started_frame_; }
   int last_ended_frame() { return last_ended_frame_; }
 
   bool IsLocked() { return compositor_lock_ != NULL; }
 
   const cc::LayerTreeDebugState& GetLayerTreeDebugState() const;
   void SetLayerTreeDebugState(const cc::LayerTreeDebugState& debug_state);
 
  private:
   friend class base::RefCounted<Compositor>;
@@ skipping 43 matching lines @@
   bool draw_on_compositing_end_;
 
   base::WeakPtrFactory<Compositor> schedule_draw_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Compositor);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_COMPOSITOR_H_