[WIP] do something :-)

Source/core/style/FillLayer.cpp

Index: Source/core/style/FillLayer.cpp
diff --git a/Source/core/style/FillLayer.cpp b/Source/core/style/FillLayer.cpp
index 693e869a88109e0921a5f74f945f2a8efe6e5989..b0816f708c26144263605a56c9816edb34750e30 100644
--- a/Source/core/style/FillLayer.cpp
+++ b/Source/core/style/FillLayer.cpp
@@ -23,24 +23,11 @@
 #include "core/style/FillLayer.h"
 
 #include "core/style/DataEquivalency.h"
+#include "wtf/SizeAssertions.h"
 
 namespace blink {
 
-struct SameSizeAsFillLayer {
-    FillLayer* m_next;
-
-    RefPtrWillBePersistent<StyleImage> m_image;
-
-    Length m_xPosition;
-    Length m_yPosition;
-
-    LengthSize m_sizeLength;
-
-    unsigned m_bitfields1;
-    unsigned m_bitfields2;
-};
-
-static_assert(sizeof(FillLayer) == sizeof(SameSizeAsFillLayer), "FillLayer should stay small");
+ASSERT_SIZE(FillLayer, 48, 56);
 
 FillLayer::FillLayer(EFillLayerType type, bool useInitialValues)
     : m_next(0)