cc: Renamed approximate{BytesUsed,OpCount} in paint op buffer.

cc/paint/drawing_display_item.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_PAINT_DRAWING_DISPLAY_ITEM_H_
 #define CC_PAINT_DRAWING_DISPLAY_ITEM_H_
 
 #include <stddef.h>
 
 #include "cc/paint/display_item.h"
 #include "cc/paint/paint_export.h"
 #include "cc/paint/paint_record.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
 
 namespace cc {
 
 class CC_PAINT_EXPORT DrawingDisplayItem : public DisplayItem {
  public:
   DrawingDisplayItem();
   explicit DrawingDisplayItem(sk_sp<const PaintRecord> record);
   explicit DrawingDisplayItem(const DrawingDisplayItem& item);
   ~DrawingDisplayItem() override;
 
   size_t ExternalMemoryUsage() const;
-  int ApproximateOpCount() const;
+  size_t OpCount() const;
 
   const sk_sp<const PaintRecord> picture;
 };
 
 }  // namespace cc
 
 #endif  // CC_PAINT_DRAWING_DISPLAY_ITEM_H_