cc/blimp: Add a LayerTreeHostRemote implementation.

cc/trees/layer_tree_host.h

 // Copyright 2016 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_TREES_LAYER_TREE_HOST_H_
 #define CC_TREES_LAYER_TREE_HOST_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "cc/base/cc_export.h"
@@ skipping 181 matching lines @@
 
   // When the main thread informs the impl thread that it is ready to commit,
   // generally it would remain blocked till the main thread state is copied to
   // the pending tree. Calling this would ensure that the main thread remains
   // blocked till the pending tree is activated.
   virtual void SetNextCommitWaitsForActivation() = 0;
 
   // The LayerTreeHost tracks whether the content is suitable for Gpu raster.
   // Calling this will reset it back to not suitable state.
   virtual void ResetGpuRasterizationTracking() = 0;
+
+ protected:
+  // Used to generate a unique identifier for a LayerTreeHost.
+  static int GenerateHostId();
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_