Introduce separate client and init path for single-threaded cc

cc/test/fake_layer_tree_host.h

 // 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.
 
 #ifndef CC_TEST_FAKE_LAYER_TREE_HOST_H_
 #define CC_TEST_FAKE_LAYER_TREE_HOST_H_
 
 #include "cc/test/fake_impl_proxy.h"
 #include "cc/test/fake_layer_tree_host_client.h"
 #include "cc/test/fake_layer_tree_host_impl.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "cc/trees/tree_synchronizer.h"
 
 namespace cc {
 
-class FakeLayerTreeHost : protected LayerTreeHost {
+class FakeLayerTreeHost : public LayerTreeHost {
  public:
   static scoped_ptr<FakeLayerTreeHost> Create();
 
   static scoped_ptr<FakeLayerTreeHost> Create(
       const LayerTreeSettings& settings);
 
   virtual ~FakeLayerTreeHost() {}
 
   virtual void SetNeedsCommit() OVERRIDE;
   virtual void SetNeedsFullTreeSync() OVERRIDE {}
 
   using LayerTreeHost::SetRootLayer;
   using LayerTreeHost::root_layer;
 
   LayerImpl* CommitAndCreateLayerImplTree();
 
   FakeLayerTreeHostImpl* host_impl() { return &host_impl_; }
   LayerTreeImpl* active_tree() { return host_impl_.active_tree(); }
 
   using LayerTreeHost::ScheduleMicroBenchmark;
   using LayerTreeHost::SetOutputSurfaceLostForTesting;
+  using LayerTreeHost::InitializeSingleThreaded;
   using LayerTreeHost::InitializeForTesting;
   void UpdateLayers(ResourceUpdateQueue* queue) {
     LayerTreeHost::UpdateLayers(queue);
   }
 
   bool needs_commit() { return needs_commit_; }
 
  private:
   FakeLayerTreeHost(LayerTreeHostClient* client,
                     const LayerTreeSettings& settings)
       : LayerTreeHost(client, NULL, settings),
         host_impl_(settings, &proxy_),
         needs_commit_(false) {}
 
   FakeImplProxy proxy_;
   FakeLayerTreeHostImpl host_impl_;
   bool needs_commit_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_FAKE_LAYER_TREE_HOST_H_