Add swap buffers posted method

BUG=228978,228897
NOTRY=true

Review URL: https://chromiumcodereview.appspot.com/13771021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@192909 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/renderer_host/compositor_impl_android.cc

@@ -388,6 +388,7 @@ CompositorImpl::OffscreenContextProviderForCompositorThread() {
 
 void CompositorImpl::OnViewContextSwapBuffersPosted() {
   TRACE_EVENT0("compositor", "CompositorImpl::OnViewContextSwapBuffersPosted");
+  client_->OnSwapBuffersPosted();
 }
 
 void CompositorImpl::OnViewContextSwapBuffersComplete() {

content/public/browser/android/compositor.h

@@ -33,6 +33,9 @@ class CONTENT_EXPORT Compositor {
 
     // The compositor has completed swapping a frame.
     virtual void OnSwapBuffersCompleted() {}
+
+    // The compositor will eventually swap a frame.
+    virtual void OnSwapBuffersPosted() {}
   };
 
   virtual ~Compositor() {}