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

cc/paint/compositing_display_item.h

Index: cc/paint/compositing_display_item.h
diff --git a/cc/paint/compositing_display_item.h b/cc/paint/compositing_display_item.h
index 266ab4d2ea8d021ee90cad04de943dae4c1f67da..ba14de004b87ee8e9a811b8f00c8b604cf7c8a92 100644
--- a/cc/paint/compositing_display_item.h
+++ b/cc/paint/compositing_display_item.h
@@ -29,7 +29,7 @@ class CC_PAINT_EXPORT CompositingDisplayItem : public DisplayItem {
     // TODO(pdr): Include color_filter's memory here.
     return 0;
   }
-  int ApproximateOpCount() const { return 1; }
+  int OpCount() const { return 1; }
 
   const uint8_t alpha;
   const SkBlendMode xfermode;
@@ -44,7 +44,7 @@ class CC_PAINT_EXPORT EndCompositingDisplayItem : public DisplayItem {
   EndCompositingDisplayItem();
   ~EndCompositingDisplayItem() override;
 
-  int ApproximateOpCount() const { return 0; }
+  int OpCount() const { return 0; }
 };
 
 }  // namespace cc