Send vsync timebase updates to the browser compositor

cc/gl_renderer.h

Index: cc/gl_renderer.h
diff --git a/cc/gl_renderer.h b/cc/gl_renderer.h
index caf7495658537109bca2de06c5756ebf07b2f148..d62185f02455332af7227bf74ff022ca3429d18d 100644
--- a/cc/gl_renderer.h
+++ b/cc/gl_renderer.h
@@ -34,6 +34,7 @@ class ScopedEnsureFramebufferAllocation;
 class CCRendererGL : public CCDirectRenderer,
                      public WebKit::WebGraphicsContext3D::WebGraphicsSwapBuffersCompleteCallbackCHROMIUM,
                      public WebKit::WebGraphicsContext3D::WebGraphicsMemoryAllocationChangedCallbackCHROMIUM ,
+                     public WebKit::WebGraphicsContext3D::WebGraphicsUpdateVSyncTimeCallbackCHROMIUM,
                      public WebKit::WebGraphicsContext3D::WebGraphicsContextLostCallback {
 public:
     static scoped_ptr<CCRendererGL> create(CCRendererClient*, CCResourceProvider*);
@@ -121,6 +122,9 @@ private:
     void discardFramebuffer();
     void ensureFramebuffer();
 
+    // WebKit::WebGraphicsContext3D::WebGraphicsUpdateVSyncTimeCallbackCHROMIUM implementation.
+    virtual void onUpdateVSyncTime(int64) OVERRIDE;

[piman, 2012/10/17 17:24:47]

There already is a mechanism to feed the vsync timing info into the compositor
(WebCompositorOutputSurfaceClient::onVSyncParametersChanged). Can we combine the
2?

[ajuma, 2012/10/17 21:15:23]

See the discussion in the WebKit bug for this issue
(https://bugs.webkit.org/show_bug.cgi?id=99592).

+
     // WebGraphicsContext3D::WebGraphicsContextLostCallback implementation.
     virtual void onContextLost() OVERRIDE;