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

cc/paint/clip_display_item.h

Index: cc/paint/clip_display_item.h
diff --git a/cc/paint/clip_display_item.h b/cc/paint/clip_display_item.h
index a969d48dd5b523b0ce988b3b11ba01f51e42d370..6a5bf0cf694c4e767d26d5368486deb471c27172 100644
--- a/cc/paint/clip_display_item.h
+++ b/cc/paint/clip_display_item.h
@@ -26,7 +26,7 @@ class CC_PAINT_EXPORT ClipDisplayItem : public DisplayItem {
   size_t ExternalMemoryUsage() const {
     return rounded_clip_rects.capacity() * sizeof(rounded_clip_rects[0]);
   }
-  int ApproximateOpCount() const { return 1; }
+  int OpCount() const { return 1; }
 
   const gfx::Rect clip_rect;
   const std::vector<SkRRect> rounded_clip_rects;
@@ -38,7 +38,7 @@ class CC_PAINT_EXPORT EndClipDisplayItem : public DisplayItem {
   EndClipDisplayItem();
   ~EndClipDisplayItem() override;
 
-  int ApproximateOpCount() const { return 0; }
+  int OpCount() const { return 0; }
 };
 
 }  // namespace cc