Decouple BrowserCompositorOutputSurface from BeginFrameSource.

content/browser/renderer_host/delegated_frame_host.h

Index: content/browser/renderer_host/delegated_frame_host.h
diff --git a/content/browser/renderer_host/delegated_frame_host.h b/content/browser/renderer_host/delegated_frame_host.h
index a24a821641fdf463c13c8a16074a1fe4a8e61db0..b2a6037254e0cb82c60da47cb3aa9eaab9710c62 100644
--- a/content/browser/renderer_host/delegated_frame_host.h
+++ b/content/browser/renderer_host/delegated_frame_host.h
@@ -81,7 +81,7 @@ class CONTENT_EXPORT DelegatedFrameHostClient {
 // the ui::Compositor associated with its DelegatedFrameHostClient.
 class CONTENT_EXPORT DelegatedFrameHost
     : public ui::CompositorObserver,
-      public ui::CompositorVSyncManager::Observer,
+      public cc::VSyncObserver,
       public ui::ContextFactoryObserver,
       public DelegatedFrameEvictorClient,
       public cc::SurfaceFactoryClient,
@@ -99,7 +99,7 @@ class CONTENT_EXPORT DelegatedFrameHost
   void OnCompositingLockStateChanged(ui::Compositor* compositor) override;
   void OnCompositingShuttingDown(ui::Compositor* compositor) override;
 
-  // ui::CompositorVSyncManager::Observer implementation.
+  // cc::VSyncObserver implementation.
   void OnUpdateVSyncParameters(base::TimeTicks timebase,
                                base::TimeDelta interval) override;