cc: Make scheduling be driven by vsync for android webview.

android_webview/browser/browser_view_renderer.h

Index: android_webview/browser/browser_view_renderer.h
diff --git a/android_webview/browser/browser_view_renderer.h b/android_webview/browser/browser_view_renderer.h
index e1388a50d62e1a00bca6200f6201758fb5fd0026..463663b881ed454b91bb7d116e9fc5ac60e4b736 100644
--- a/android_webview/browser/browser_view_renderer.h
+++ b/android_webview/browser/browser_view_renderer.h
@@ -49,6 +49,8 @@ class BrowserViewRenderer : public content::SynchronousCompositorClient {
   bool OnDrawHardware();
   bool OnDrawSoftware(SkCanvas* canvas);
 
+  void OnVSync(base::TimeTicks frame_time, base::TimeDelta vsync_period);
+
   // CapturePicture API methods.
   skia::RefPtr<SkPicture> CapturePicture(int width, int height);
   void EnableOnNewPicture(bool enabled);
@@ -84,7 +86,8 @@ class BrowserViewRenderer : public content::SynchronousCompositorClient {
       content::SynchronousCompositor* compositor) override;
   virtual void DidDestroyCompositor(content::SynchronousCompositor* compositor)
       override;
-  virtual void SetContinuousInvalidate(bool invalidate) override;
+  virtual void SetNeedsVSyncs(bool needs_vsyncs) override;
+  virtual void PostInvalidate() override;
   virtual void DidUpdateContent() override;
   virtual gfx::Vector2dF GetTotalRootLayerScrollOffset() override;
   virtual void UpdateRootLayerState(
@@ -100,44 +103,26 @@ class BrowserViewRenderer : public content::SynchronousCompositorClient {
                              gfx::Vector2dF current_fling_velocity) override;
 
   void UpdateParentDrawConstraints();
-  void DidSkipCommitFrame();
   void InvalidateOnFunctorDestroy();
 
  private:
-  void SetTotalRootLayerScrollOffset(gfx::Vector2dF new_value_dip);
-  // Checks the continuous invalidate and block invalidate state, and schedule
-  // invalidates appropriately. If |force_invalidate| is true, then send a view
-  // invalidate regardless of compositor expectation. If |skip_reschedule_tick|
-  // is true and if there is already a pending fallback tick, don't reschedule
-  // them.
-  void EnsureContinuousInvalidation(bool force_invalidate,
-                                    bool skip_reschedule_tick);
   bool CompositeSW(SkCanvas* canvas);
-  void DidComposite();
-  void DidSkipCompositeInDraw();
+  scoped_ptr<cc::CompositorFrame> CompositeHw();
+
+  void SetTotalRootLayerScrollOffset(gfx::Vector2dF new_value_dip);
   scoped_refptr<base::debug::ConvertableToTraceFormat> RootLayerStateAsValue(
       const gfx::Vector2dF& total_scroll_offset_dip,
       const gfx::SizeF& scrollable_size_dip);
 
-  scoped_ptr<cc::CompositorFrame> CompositeHw();
   void ReturnUnusedResource(scoped_ptr<cc::CompositorFrame> frame);
   void ReturnResourceFromParent();
-
-  // If we call up view invalidate and OnDraw is not called before a deadline,
-  // then we keep ticking the SynchronousCompositor so it can make progress.
-  // Do this in a two stage tick due to native MessageLoop favors delayed task,
-  // so ensure delayed task is inserted only after the draw task returns.
-  void PostFallbackTick();
-  void FallbackTickFired();
-
-  // Force invoke the compositor to run produce a 1x1 software frame that is
-  // immediately discarded. This is a hack to force invoke parts of the
-  // compositor that are not directly exposed here.
-  void ForceFakeCompositeSW();
-
+ 
   gfx::Vector2d max_scroll_offset() const;
 
   size_t CalculateDesiredMemoryPolicy();
+
+  void UpdateNeedsVSyncs();
+
   // For debug tracing or logging. Return the string representation of this
   // view renderer's state.
   std::string ToString() const;
@@ -165,20 +150,16 @@ class BrowserViewRenderer : public content::SynchronousCompositorClient {
   // tiling priority.
   ParentCompositorDrawConstraints parent_draw_constraints_;
 
-  // When true, we should continuously invalidate and keep drawing, for example
+  // When true, we should ask for vsyncs and pass them on, for example
   // to drive animation. This value is set by the compositor and should always
   // reflect the expectation of the compositor and not be reused for other
   // states.
-  bool compositor_needs_continuous_invalidate_;
-
-  bool invalidate_after_composite_;
-
-  // Used to block additional invalidates while one is already pending.
-  bool block_invalidates_;
+  bool compositor_needs_vsyncs_;
 
-  base::CancelableClosure post_fallback_tick_;
-  base::CancelableClosure fallback_tick_fired_;
-  bool fallback_tick_pending_;
+  // This is actually used to decide if we're asking for vsyncs. Sometimes we
+  // want to stop vsync callbacks even if the compositor is asking for them.
+  // e.g. when paused (backgrounded) or window not visible.
+  bool needs_vsyncs_;
 
   gfx::Size size_;