[cc] Add and use BeginFrameAck for DidFinishFrame.

ui/android/window_android.cc

Index: ui/android/window_android.cc
diff --git a/ui/android/window_android.cc b/ui/android/window_android.cc
index 33c5fb4c9e6ca8c854c830fd5af48f02583d8696..9e552a82403bf869cff1659a32a2e7022b67095c 100644
--- a/ui/android/window_android.cc
+++ b/ui/android/window_android.cc
@@ -39,7 +39,7 @@ class WindowAndroid::WindowBeginFrameSource : public cc::BeginFrameSource {
   void AddObserver(cc::BeginFrameObserver* obs) override;
   void RemoveObserver(cc::BeginFrameObserver* obs) override;
   void DidFinishFrame(cc::BeginFrameObserver* obs,
-                      size_t remaining_frames) override {}
+                      const cc::BeginFrameAck& ack) override {}
   bool IsThrottled() const override { return true; }
 
   void OnVSync(base::TimeTicks frame_time, base::TimeDelta vsync_period);