cc: Unify use of DidSwapBuffers() and did_request_swap

cc/trees/thread_proxy.h

Index: cc/trees/thread_proxy.h
diff --git a/cc/trees/thread_proxy.h b/cc/trees/thread_proxy.h
index f91599ed703d67e8f23df0d1aea6889d2fefafd3..4ffae4acf07d9218645ffc3de4d7671b2297a4cc 100644
--- a/cc/trees/thread_proxy.h
+++ b/cc/trees/thread_proxy.h
@@ -110,10 +110,9 @@ class ThreadProxy : public Proxy,
   virtual void SetNeedsBeginFrame(bool enable) OVERRIDE;
   virtual void WillBeginImplFrame(const BeginFrameArgs& args) OVERRIDE;
   virtual void ScheduledActionSendBeginMainFrame() OVERRIDE;
-  virtual DrawSwapReadbackResult ScheduledActionDrawAndSwapIfPossible()
-      OVERRIDE;
-  virtual DrawSwapReadbackResult ScheduledActionDrawAndSwapForced() OVERRIDE;
-  virtual DrawSwapReadbackResult ScheduledActionDrawAndReadback() OVERRIDE;
+  virtual DrawResult ScheduledActionDrawAndSwapIfPossible() OVERRIDE;
+  virtual DrawResult ScheduledActionDrawAndSwapForced() OVERRIDE;
+  virtual DrawResult ScheduledActionDrawAndReadback() OVERRIDE;
   virtual void ScheduledActionAnimate() OVERRIDE;
   virtual void ScheduledActionCommit() OVERRIDE;
   virtual void ScheduledActionUpdateVisibleTiles() OVERRIDE;
@@ -182,9 +181,9 @@ class ThreadProxy : public Proxy,
       RendererCapabilities* capabilities);
   void FinishGLOnImplThread(CompletionEvent* completion);
   void LayerTreeHostClosedOnImplThread(CompletionEvent* completion);
-  DrawSwapReadbackResult DrawSwapReadbackInternal(bool forced_draw,
-                                                  bool swap_requested,
-                                                  bool readback_requested);
+  DrawResult DrawSwapReadbackInternal(bool forced_draw,
+                                      bool swap_requested,
+                                      bool readback_requested);
   void ForceSerializeOnSwapBuffersOnImplThread(CompletionEvent* completion);
   void CheckOutputSurfaceStatusOnImplThread();
   void CommitPendingOnImplThreadForTesting(CommitPendingRequest* request);