RendererGLContext supports reparenting a GL context.

content/renderer/gpu/command_buffer_proxy.h

 // Copyright (c) 2011 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 CONTENT_RENDERER_GPU_COMMAND_BUFFER_PROXY_H_
 #define CONTENT_RENDERER_GPU_COMMAND_BUFFER_PROXY_H_
 #pragma once
 
 #if defined(ENABLE_GPU)
 
@@ skipping 43 matching lines @@
   virtual int32 CreateTransferBuffer(size_t size, int32 id_request);
   virtual int32 RegisterTransferBuffer(base::SharedMemory* shared_memory,
                                        size_t size,
                                        int32 id_request);
   virtual void DestroyTransferBuffer(int32 id);
   virtual gpu::Buffer GetTransferBuffer(int32 handle);
   virtual void SetToken(int32 token);
   virtual void SetParseError(gpu::error::Error error);
   virtual void OnSwapBuffers();
 
+  // Reparent a command buffer. TODO(apatrick): going forward, the notion of
+  // the parent / child relationship between command buffers is going away in
+  // favor of the notion of surfaces that can be drawn to in one command buffer
+  // and bound as a texture in any other.
+  virtual bool SetParent(CommandBufferProxy* parent_command_buffer,
+                         uint32 parent_texture_id);
+
   // Set a callback that will be invoked when the SwapBuffers call has been
   // issued.
   void SetSwapBuffersCallback(Callback0::Type* callback);
   void SetChannelErrorCallback(Callback0::Type* callback);
 
   // Asynchronously resizes an offscreen frame buffer.
   void ResizeOffscreenFrameBuffer(const gfx::Size& size);
 
   // Set a task that will be invoked the next time the window becomes invalid
   // and needs to be repainted. Takes ownership of task.
@@ skipping 39 matching lines @@
 
   scoped_ptr<Callback0::Type> swap_buffers_callback_;
   scoped_ptr<Callback0::Type> channel_error_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(CommandBufferProxy);
 };
 
 #endif  // ENABLE_GPU
 
 #endif  // CONTENT_RENDERER_GPU_COMMAND_BUFFER_PROXY_H_