Remove unused field draws_content_ from WebContentLayerImpl.

cc/blink/web_content_layer_impl.h

 // 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.
 
 #ifndef CC_BLINK_WEB_CONTENT_LAYER_IMPL_H_
 #define CC_BLINK_WEB_CONTENT_LAYER_IMPL_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "cc/blink/cc_blink_export.h"
 #include "cc/blink/web_layer_impl.h"
@@ skipping 24 matching lines @@
 
   // ContentLayerClient implementation.
   scoped_refptr<cc::DisplayItemList> PaintContentsToDisplayList(
       const gfx::Rect& clip,
       PaintingControlSetting painting_control) override;
   bool FillsBoundsCompletely() const override;
   size_t GetApproximateUnsharedMemoryUsage() const override;
 
   scoped_ptr<WebLayerImpl> layer_;
   blink::WebContentLayerClient* client_;
-  bool draws_content_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WebContentLayerImpl);
 };
 
 }  // namespace cc_blink
 
 #endif  // CC_BLINK_WEB_CONTENT_LAYER_IMPL_H_