Android: Move scheduling logic to CompositorImpl

content/browser/renderer_host/compositor_impl_android.h

Index: content/browser/renderer_host/compositor_impl_android.h
diff --git a/content/browser/renderer_host/compositor_impl_android.h b/content/browser/renderer_host/compositor_impl_android.h
index 969b1142285f53db11578d47793e0791ca92c900..cd10780b98752fa9d58b213a163aebbde2598130 100644
--- a/content/browser/renderer_host/compositor_impl_android.h
+++ b/content/browser/renderer_host/compositor_impl_android.h
@@ -9,6 +9,7 @@
 #include "base/compiler_specific.h"
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "cc/resources/ui_resource_client.h"
 #include "cc/trees/layer_tree_host_client.h"
 #include "cc/trees/layer_tree_host_single_thread_client.h"
@@ -63,7 +64,7 @@ class CONTENT_EXPORT CompositorImpl
   virtual void SetHasTransparentBackground(bool flag) OVERRIDE;
   virtual bool CompositeAndReadback(
       void *pixels, const gfx::Rect& rect) OVERRIDE;
-  virtual void Composite() OVERRIDE;
+  virtual void SetNeedsComposite() OVERRIDE;
   virtual cc::UIResourceId GenerateUIResource(const SkBitmap& bitmap,
                                               bool is_transient) OVERRIDE;
   virtual cc::UIResourceId GenerateCompressedUIResource(const gfx::Size& size,
@@ -76,7 +77,7 @@ class CONTENT_EXPORT CompositorImpl
   virtual void WillBeginMainFrame(int frame_id) OVERRIDE {}
   virtual void DidBeginMainFrame() OVERRIDE {}
   virtual void Animate(base::TimeTicks frame_begin_time) OVERRIDE {}
-  virtual void Layout() OVERRIDE {}
+  virtual void Layout() OVERRIDE;
   virtual void ApplyScrollAndScale(const gfx::Vector2d& scroll_delta,
                                    float page_scale) OVERRIDE {}
   virtual scoped_ptr<cc::OutputSurface> CreateOutputSurface(bool fallback)
@@ -98,8 +99,12 @@ class CONTENT_EXPORT CompositorImpl
 
   // WindowAndroidCompositor implementation.
   virtual void AttachLayerForReadback(scoped_refptr<cc::Layer> layer) OVERRIDE;
+  virtual void OnVSync(base::TimeTicks frame_time,
+                       base::TimeDelta vsync_period) OVERRIDE;
 
  private:
+  void PostComposite(base::TimeDelta delay);
+  void Composite(bool is_vsync);

[Sami, 2014/05/09 13:21:14]

Mind making this an enum -- CompositingTrigger or something? I'm allergic to
opaque bool parameters :)

[no sievers, 2014/05/09 22:53:44]

Done.

   cc::UIResourceId GenerateUIResourceFromUIResourceBitmap(
       const cc::UIResourceBitmap& bitmap,
       bool is_transient);
@@ -122,6 +127,33 @@ class CONTENT_EXPORT CompositorImpl
 
   gfx::NativeWindow root_window_;
 
+  // Used locally to track whether a call to LTH::Composite() did result in
+  // a posted SwapBuffers().
+  bool did_post_swapbuffers_;
+
+  // Used locally to inhibit ScheduleComposite() during Layout().
+  bool ignore_schedule_composite_;
+
+  // Whether we need to composite in general because of any invalidation or
+  // explicit request.
+  bool needs_composite_;
+
+  // When SetNeedsComposite() is getting called, we will try to schedule

[Sami, 2014/05/09 13:21:14]

This explanation should probably go next to SetNeedsComposite. ScheduleComposite
could also use a comment about what the difference between the two is.

[no sievers, 2014/05/09 22:53:44]

ScheduleComposite is the LTHClient implementation. I've made the whole derived
implementation private and added comments inside both functions.

Compositor::SetNeedsComposite() has a general comment about when it should be
called in the public header.

+  // regularly during vsync.
+  bool should_composite_on_vsync_;
+
+  // Whether we composited immediately outside of a vsync callback since
+  // the last tick.
+  bool did_composite_outside_vsync_;

[Sami, 2014/05/09 13:21:14]

Would something did_composite_during_this_frame_ be simpler? No matter why we
composite, we only want to do it once per frame.

[no sievers, 2014/05/09 22:53:44]

Done.

+
+  // The number of SwapBuffer calls that have not returned and ACK'd from
+  // the GPU thread.
+  unsigned int pending_swapbuffers_;
+
+  base::TimeDelta vsync_period_;
+
+  base::WeakPtrFactory<CompositorImpl> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(CompositorImpl);
 };