Start using deferred rendering for WebView on L.

ui/gl/android/surface_texture.h

Index: ui/gl/android/surface_texture.h
diff --git a/ui/gl/android/surface_texture.h b/ui/gl/android/surface_texture.h
index b0ffc90f17f911f9ffe68668ecb052c1e69135a6..65c0f48506af42940f8a3ea84a6566e0a871753a 100644
--- a/ui/gl/android/surface_texture.h
+++ b/ui/gl/android/surface_texture.h
@@ -37,6 +37,14 @@ class GL_EXPORT SurfaceTexture
   // via a weak ref).
   void SetFrameAvailableCallbackOnAnyThread(const base::Closure& callback);
 
+  // Set the listener callback on a thread that is run on a thread that is
+  // dedicated to frame available callbacks.  This thread will be shared with
+  // other frame available callbacks.  This is used for WebView, when the
+  // callback normally comes in on the main thread, but the main thread is
+  // busy doing composition.
+  // This requires API level 21 or later.
+  void SetFrameAvailableCallbackOnSeparateThread(const base::Closure& callback);
+
   // Update the texture image to the most recent frame from the image stream.
   void UpdateTexImage();