Break Sky's dependency on cc

sky/viewer/platform/platform_impl.cc

 // Copyright 2014 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 "sky/viewer/platform/platform_impl.h"
 
 #include <cmath>
 
 #include "base/debug/trace_event.h"
 #include "base/files/file_path.h"
@@ skipping 100 matching lines @@
 
 base::SingleThreadTaskRunner* PlatformImpl::mainThreadTaskRunner() {
   return main_thread_task_runner_.get();
 }
 
 bool PlatformImpl::isThreadedCompositingEnabled() {
   return true;
 }
 
 blink::WebCompositorSupport* PlatformImpl::compositorSupport() {
-  return &compositor_support_;
+  return nullptr;
 }
 
 mojo::NetworkService* PlatformImpl::networkService() {
   return network_service_.get();
 }
 
 blink::WebURLLoader* PlatformImpl::createURLLoader() {
   return new WebURLLoaderImpl(network_service_.get());
 }
 
@@ skipping 116 matching lines @@
   else
     CHECK(false);
 
   std::string buffer;
   base::ReadFileToString(path, &buffer);
   CHECK(!buffer.empty());
   return blink::WebData(buffer.data(), buffer.size());
 }
 
 }  // namespace sky