Remove offscreen compositor contexts.

mojo/examples/compositor_app/compositor_host.cc

 // 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.
 
 #include "mojo/examples/compositor_app/compositor_host.h"
 
 #include "cc/layers/layer.h"
 #include "cc/layers/solid_color_layer.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
@@ skipping 65 matching lines @@
       new cc::OutputSurface(new MojoContextProvider(gl_pipe_.Pass())));
 }
 
 void CompositorHost::DidInitializeOutputSurface(bool success) {}
 
 void CompositorHost::WillCommit() {}
 void CompositorHost::DidCommit() {}
 void CompositorHost::DidCommitAndDrawFrame() {}
 void CompositorHost::DidCompleteSwapBuffers() {}
 
-scoped_refptr<cc::ContextProvider> CompositorHost::OffscreenContextProvider() {
-  return NULL;
-}
-
 }  // namespace examples
 }  // namespace mojo