Implemented support for GL constext share groups in the renderer process.

content/common/gpu/gpu_command_buffer_stub.h

Index: content/common/gpu/gpu_command_buffer_stub.h
===================================================================
--- content/common/gpu/gpu_command_buffer_stub.h	(revision 95161)
+++ content/common/gpu/gpu_command_buffer_stub.h	(working copy)
@@ -17,6 +17,7 @@
 #include "base/task.h"
 #include "content/common/gpu/media/gpu_video_decode_accelerator.h"
 #include "gpu/command_buffer/service/command_buffer_service.h"
+#include "gpu/command_buffer/service/context_group.h"
 #include "gpu/command_buffer/service/gpu_scheduler.h"
 #include "ipc/ipc_channel.h"
 #include "ipc/ipc_message.h"
@@ -33,6 +34,7 @@
  public:
   GpuCommandBufferStub(
       GpuChannel* channel,
+      GpuCommandBufferStub* share_group,
       gfx::PluginWindowHandle handle,
       const gfx::Size& size,
       const gpu::gles2::DisallowedExtensions& disallowed_extensions,
@@ -133,6 +135,9 @@
   // are destroyed. So a raw pointer is safe.
   GpuChannel* channel_;
 
+  // The group of contexts that share namespaces with this context.
+  scoped_refptr<gpu::gles2::ContextGroup> context_group_;
+
   gfx::PluginWindowHandle handle_;
   gfx::Size initial_size_;
   gpu::gles2::DisallowedExtensions disallowed_extensions_;