Remove unused offscreen_context_provider variable.

cc/trees/layer_tree_host_impl.h

 // Copyright 2011 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_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <list>
 #include <set>
 #include <string>
@@ skipping 565 matching lines @@
   typedef base::hash_map<UIResourceId, UIResourceData>
       UIResourceMap;
   UIResourceMap ui_resource_map_;
 
   // Resources that were evicted by EvictAllUIResources. Resources are removed
   // from this when they are touched by a create or destroy from the UI resource
   // request queue.
   std::set<UIResourceId> evicted_ui_resources_;
 
   scoped_ptr<OutputSurface> output_surface_;
-  scoped_refptr<ContextProvider> offscreen_context_provider_;
 
   // |resource_provider_| and |tile_manager_| can be NULL, e.g. when using tile-
   // free rendering - see OutputSurface::ForcedDrawToSoftwareDevice().
   scoped_ptr<ResourceProvider> resource_provider_;
   scoped_ptr<TileManager> tile_manager_;
   bool use_gpu_rasterization_;
   scoped_ptr<RasterWorkerPool> raster_worker_pool_;
   scoped_ptr<ResourcePool> resource_pool_;
   scoped_ptr<ResourcePool> staging_resource_pool_;
   scoped_ptr<Renderer> renderer_;
@@ skipping 111 matching lines @@
 
   std::vector<PictureLayerImpl*> picture_layers_;
   std::vector<PictureLayerImpl::Pair> picture_layer_pairs_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_