Aura: Have ui::Layer implement WebKit::WebExternalTextureLayerClient

With --ui-enable-threaded-compositing, every Layer::SetExternalTexture() was causing a heavy CCThreadProxy::acquireLayerTextures(). This synchronization is unnecessary on the common case of buffer flips, because RWHVA handles the necessary synchronization via OnCompositingWillStart callbacks.

To reduce the synchronization burden, we handle
- wait for a commit on resize fast ACKS
- handle the common case of buffer flips via WebExternalTextureLayerClient::prepareTexture()
- and explicitly call WebExternalTextureLayer::willModifyTexture() when we need the extra synchronization on tear down.

BUG=136012
TEST=none

Review URL: https://chromiumcodereview.appspot.com/10689108

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@146621 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 8 insertions, 0 deletions

diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index 0b129cf..ea57724 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -101,6 +101,7 @@ class COMPOSITOR_EXPORT Texture : public base::RefCounted<Texture> {
   void set_texture_id(unsigned int id) { texture_id_ = id; }
   bool flipped() const { return flipped_; }
   gfx::Size size() const { return size_; }
+  virtual WebKit::WebGraphicsContext3D* HostContext3D() = 0;
 
  protected:
   virtual ~Texture();
@@ -190,6 +191,10 @@ class COMPOSITOR_EXPORT Compositor
   // and the OnCompositingEnded.
   bool DrawPending() const { return swap_posted_; }
 
+  // Returns whether the drawing is issued from a separate thread
+  // (i.e. |Compositor::Initialize(true)| was called).
+  bool IsThreaded() const;
+
   // Internal functions, called back by command-buffer contexts on swap buffer
   // events.
 
@@ -209,6 +214,7 @@ class COMPOSITOR_EXPORT Compositor
                                    float scaleFactor);
   virtual WebKit::WebGraphicsContext3D* createContext3D();
   virtual void didRebindGraphicsContext(bool success);
+  virtual void didCommit();
   virtual void didCommitAndDrawFrame();
   virtual void didCompleteSwapBuffers();
   virtual void scheduleComposite();
@@ -251,6 +257,8 @@ class COMPOSITOR_EXPORT Compositor
   int last_ended_frame_;
 
   bool disable_schedule_composite_;
+
+  DISALLOW_COPY_AND_ASSIGN(Compositor);
 };
 
 }  // namespace ui