Reland of Client side display item cache flag

third_party/WebKit/Source/core/layout/LayoutObject.cpp

Index: third_party/WebKit/Source/core/layout/LayoutObject.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.cpp b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
index 92d0bd70c935e2b98cc76bfd53922962c3be6be9..d5c018803aaefea4f2d582aa94c6e12f3dc8aa0f 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -140,6 +140,7 @@ struct SameSizeAsLayoutObject {
     unsigned m_bitfields2;
     LayoutRect rect; // Stores the previous paint invalidation rect.
     LayoutPoint position; // Stores the previous position from the paint invalidation container.
+    DisplayItemCacheGeneration cacheGeneration;
 };
 
 static_assert(sizeof(LayoutObject) == sizeof(SameSizeAsLayoutObject), "LayoutObject should stay small");