Clean up some dead code accidentally left around in cc DisplayItem subtypes.

cc/playback/compositing_display_item.h

 // Copyright 2015 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_PLAYBACK_COMPOSITING_DISPLAY_ITEM_H_
 #define CC_PLAYBACK_COMPOSITING_DISPLAY_ITEM_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 64 matching lines @@
                   ImageSerializationProcessor* image_serialization_processor)
       const override;
   void Raster(SkCanvas* canvas,
               const gfx::Rect& canvas_target_playback_rect,
               SkPicture::AbortCallback* callback) const override;
   void AsValueInto(const gfx::Rect& visual_rect,
                    base::trace_event::TracedValue* array) const override;
   size_t ExternalMemoryUsage() const override;
 
   int ApproximateOpCount() const { return 0; }
-  bool IsSuitableForGpuRasterization() const { return true; }
 };
 
 }  // namespace cc
 
 #endif  // CC_PLAYBACK_COMPOSITING_DISPLAY_ITEM_H_