Make NinePieceImageData use RefCountedCopyable.

third_party/WebKit/Source/core/style/NinePieceImage.cpp

Index: third_party/WebKit/Source/core/style/NinePieceImage.cpp
diff --git a/third_party/WebKit/Source/core/style/NinePieceImage.cpp b/third_party/WebKit/Source/core/style/NinePieceImage.cpp
index c9bd3de84b573d71cc1fd0900367173fe60a125c..a185d9481d612bd57d25b1264280d920439da621 100644
--- a/third_party/WebKit/Source/core/style/NinePieceImage.cpp
+++ b/third_party/WebKit/Source/core/style/NinePieceImage.cpp
@@ -69,16 +69,6 @@ NinePieceImageData::NinePieceImageData()
              Length(0, kFixed),
              Length(0, kFixed)) {}
 
-NinePieceImageData::NinePieceImageData(const NinePieceImageData& other)
-    : RefCounted<NinePieceImageData>(),
-      fill(other.fill),
-      horizontal_rule(other.horizontal_rule),
-      vertical_rule(other.vertical_rule),
-      image(other.image),
-      image_slices(other.image_slices),
-      border_slices(other.border_slices),
-      outset(other.outset) {}
-
 bool NinePieceImageData::operator==(const NinePieceImageData& other) const {
   return DataEquivalent(image, other.image) &&
          image_slices == other.image_slices && fill == other.fill &&