Added CommandBuffer::GetLastError.

content/renderer/gpu/command_buffer_proxy.h

Index: content/renderer/gpu/command_buffer_proxy.h
===================================================================
--- content/renderer/gpu/command_buffer_proxy.h	(revision 119905)
+++ content/renderer/gpu/command_buffer_proxy.h	(working copy)
@@ -91,6 +91,12 @@
       media::VideoDecodeAccelerator::Profile profile,
       media::VideoDecodeAccelerator::Client* client);
 
+  // TODO(apatrick): this is a temporary optimization while skia is calling
+  // RendererGLContext::MakeCurrent prior to every GL call. It saves returning 6
+  // ints redundantly when only the error is needed for the CommandBufferProxy
+  // implementation.
+  virtual gpu::error::Error GetLastError() OVERRIDE;
+
  private:
   // Send an IPC message over the GPU channel. This is private to fully
   // encapsulate the channel; all callers of this function must explicitly