Dynamically set CAOpenGLLAyer to be asynchronous

content/browser/renderer_host/compositing_iosurface_layer_mac.h

Index: content/browser/renderer_host/compositing_iosurface_layer_mac.h
diff --git a/content/browser/renderer_host/compositing_iosurface_layer_mac.h b/content/browser/renderer_host/compositing_iosurface_layer_mac.h
index a03ab1cb5dfd9beb4711c0576c6979b63177f320..af5d5b38e9dff943372ce880702184a018fa64f8 100644
--- a/content/browser/renderer_host/compositing_iosurface_layer_mac.h
+++ b/content/browser/renderer_host/compositing_iosurface_layer_mac.h
@@ -20,6 +20,11 @@ class RenderWidgetHostViewMac;
  @private
   content::RenderWidgetHostViewMac* renderWidgetHostView_;
   scoped_refptr<content::CompositingIOSurfaceContext> context_;
+
+  // Used to track when canDrawInCGLContext should return YES. This can be
+  // in response to receiving a new compositor frame, or from any of the events
+  // that cause setNeedsDisplay to be called on the layer.
+  BOOL needsDisplay_;
 }
 
 @property(nonatomic, readonly)
@@ -35,6 +40,13 @@ class RenderWidgetHostViewMac;
 // |renderWidgetHostView_| is no longer valid and may no longer be dereferenced.
 - (void)disableCompositing;
 
+// Called when a new frame is received.
+- (void)gotNewFrame;
+
+// Called when it has been a while since a new frame has been received, and the
+// layer should become not-asynchronous.
+- (void)timerSinceGotNewFrameFired;
+
 @end
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_COMPOSITING_IOSURFACE_LAYER_MAC_H_