cc: Introduce BeginFrame sequence numbers and acknowledgements.

ui/android/delegated_frame_host_android.h

Index: ui/android/delegated_frame_host_android.h
diff --git a/ui/android/delegated_frame_host_android.h b/ui/android/delegated_frame_host_android.h
index 77479e22c3593e967ad7576ff7f17fb902e10e3a..977f03b053d977efb1bdf03e0d9f8bf71d90c6a5 100644
--- a/ui/android/delegated_frame_host_android.h
+++ b/ui/android/delegated_frame_host_android.h
@@ -32,12 +32,16 @@ class WindowAndroidCompositor;
 class UI_ANDROID_EXPORT DelegatedFrameHostAndroid
     : public cc::SurfaceFactoryClient {
  public:
-  using ReturnResourcesCallback =
-      base::Callback<void(const cc::ReturnedResourceArray&)>;
+  class Client {
+   public:
+    virtual void SetBeginFrameSource(
+        cc::BeginFrameSource* begin_frame_source) = 0;
+    virtual void ReturnResources(const cc::ReturnedResourceArray&) = 0;
+  };
 
   DelegatedFrameHostAndroid(ViewAndroid* view,
                             SkColor background_color,
-                            ReturnResourcesCallback return_resources_callback);
+                            Client* client);
 
   ~DelegatedFrameHostAndroid() override;
 
@@ -81,7 +85,7 @@ class UI_ANDROID_EXPORT DelegatedFrameHostAndroid
   cc::SurfaceManager* surface_manager_;
   std::unique_ptr<cc::SurfaceIdAllocator> surface_id_allocator_;
   cc::FrameSinkId registered_parent_frame_sink_id_;
-  ReturnResourcesCallback return_resources_callback_;
+  Client* client_;
 
   std::unique_ptr<cc::SurfaceFactory> surface_factory_;