[Slimming Paint] Blink-side contiguous allocation of display items.

Source/platform/graphics/paint/TransformDisplayItem.cpp

Index: Source/platform/graphics/paint/TransformDisplayItem.cpp
diff --git a/Source/platform/graphics/paint/TransformDisplayItem.cpp b/Source/platform/graphics/paint/TransformDisplayItem.cpp
index 50da105acc9a893fa2b2866786534d649f77dcd8..677461b9e0241ea7532f377b2a36d27d89949ac6 100644
--- a/Source/platform/graphics/paint/TransformDisplayItem.cpp
+++ b/Source/platform/graphics/paint/TransformDisplayItem.cpp
@@ -6,6 +6,7 @@
 #include "platform/graphics/paint/TransformDisplayItem.h"
 
 #include "platform/graphics/GraphicsContext.h"
+#include "platform/graphics/paint/DisplayItems.h"
 #include "platform/transforms/AffineTransform.h"
 #include "public/platform/WebDisplayItemList.h"
 
@@ -22,6 +23,12 @@ void BeginTransformDisplayItem::appendToWebDisplayItemList(WebDisplayItemList* l
     list->appendTransformItem(affineTransformToSkMatrix(m_transform));
 }
 
+void BeginTransformDisplayItem::appendByMoving(DisplayItems& destination)
+{
+    destination.emplaceBack<BeginTransformDisplayItem>(
+        DisplayItemClientWrapperHelper(*this), m_transform);
+}
+
 #ifndef NDEBUG
 void BeginTransformDisplayItem::dumpPropertiesAsDebugString(WTF::StringBuilder& stringBuilder) const
 {
@@ -41,4 +48,10 @@ void EndTransformDisplayItem::appendToWebDisplayItemList(WebDisplayItemList* lis
     list->appendEndTransformItem();
 }
 
+void EndTransformDisplayItem::appendByMoving(DisplayItems& destination)
+{
+    destination.emplaceBack<EndTransformDisplayItem>(
+        DisplayItemClientWrapperHelper(*this));
+}
+
 } // namespace blink