Fix alignment issue of ContiguousContainer

third_party/WebKit/Source/platform/graphics/paint/CachedDisplayItem.h

Index: third_party/WebKit/Source/platform/graphics/paint/CachedDisplayItem.h
diff --git a/third_party/WebKit/Source/platform/graphics/paint/CachedDisplayItem.h b/third_party/WebKit/Source/platform/graphics/paint/CachedDisplayItem.h
index 24b28887639db3f9d907458e1e8f82f492473f77..e030dc2b8729df3e825aba03ee8c8aed475c2081 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/CachedDisplayItem.h
+++ b/third_party/WebKit/Source/platform/graphics/paint/CachedDisplayItem.h
@@ -13,10 +13,10 @@ namespace blink {
 // A placeholder of a DrawingDisplayItem or a subtree in the new paint DisplayItemList,
 // to indicate that the DrawingDisplayItem/subtree has not been changed and should be replaced with
 // the cached DrawingDisplayItem/subtree when merging new paint list to cached paint list.
-class CachedDisplayItem final : public DisplayItem {
+class CachedDisplayItem final : public DisplayItemBase<CachedDisplayItem> {
 public:
     CachedDisplayItem(const DisplayItemClient& client, Type type)
-        : DisplayItem(client, type, sizeof(*this))
+        : DisplayItemBase(client, type)
     {
         ASSERT(isCachedType(type));
     }