Start using deferred rendering for WebView on L.

ui/gl/android/surface_texture.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_GL_ANDROID_SURFACE_TEXTURE_H_
 #define UI_GL_ANDROID_SURFACE_TEXTURE_H_
 
 #include <jni.h>
 
 #include "base/android/scoped_java_ref.h"
@@ skipping 19 matching lines @@
   // being referenced from the callback, the only robust way here is to create
   // the callback from a weak pointer to your object.
   void SetFrameAvailableCallback(const base::Closure& callback);
 
   // Set the listener callback, but allow it to be invoked on any thread.  The
   // same caveats apply as SetFrameAvailableCallback, plus whatever other issues
   // show up due to multithreading (e.g., don't bind the Closure to a method
   // 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();
 
   // Retrieve the 4x4 texture coordinate transform matrix associated with the
   // texture image set by the most recent call to updateTexImage.
   void GetTransformMatrix(float mtx[16]);
 
   // Attach the SurfaceTexture to the texture currently bound to
   // GL_TEXTURE_EXTERNAL_OES.
   void AttachToGLContext();
@@ skipping 23 matching lines @@
 
   // Java SurfaceTexture instance.
   base::android::ScopedJavaGlobalRef<jobject> j_surface_texture_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfaceTexture);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_ANDROID_SURFACE_TEXTURE_H_