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

Source/platform/graphics/paint/FloatClipDisplayItem.cpp

Index: Source/platform/graphics/paint/FloatClipDisplayItem.cpp
diff --git a/Source/platform/graphics/paint/FloatClipDisplayItem.cpp b/Source/platform/graphics/paint/FloatClipDisplayItem.cpp
index 619c1c0e0b731152eacb628d93082b04687b3816..6445ee8103cce19deffe44574c772082ac3ab43b 100644
--- a/Source/platform/graphics/paint/FloatClipDisplayItem.cpp
+++ b/Source/platform/graphics/paint/FloatClipDisplayItem.cpp
@@ -6,6 +6,7 @@
 #include "platform/graphics/paint/FloatClipDisplayItem.h"
 
 #include "platform/graphics/GraphicsContext.h"
+#include "platform/graphics/paint/DisplayItems.h"
 #include "public/platform/WebDisplayItemList.h"
 #include "third_party/skia/include/core/SkScalar.h"
 
@@ -22,6 +23,12 @@ void FloatClipDisplayItem::appendToWebDisplayItemList(WebDisplayItemList* list)
     list->appendFloatClipItem(m_clipRect);
 }
 
+void FloatClipDisplayItem::appendByMoving(DisplayItems& destination)
+{
+    destination.emplaceBack<FloatClipDisplayItem>(
+        DisplayItemClientWrapperHelper(*this), type(), m_clipRect);
+}
+
 void EndFloatClipDisplayItem::replay(GraphicsContext& context)
 {
     context.restore();
@@ -32,6 +39,12 @@ void EndFloatClipDisplayItem::appendToWebDisplayItemList(WebDisplayItemList* lis
     list->appendEndFloatClipItem();
 }
 
+void EndFloatClipDisplayItem::appendByMoving(DisplayItems& destination)
+{
+    destination.emplaceBack<EndFloatClipDisplayItem>(
+        DisplayItemClientWrapperHelper(*this), type());
+}
+
 #ifndef NDEBUG
 void FloatClipDisplayItem::dumpPropertiesAsDebugString(WTF::StringBuilder& stringBuilder) const
 {