Blink-side contiguous allocation of display items.

Source/platform/graphics/paint/CompositingDisplayItem.h

Index: Source/platform/graphics/paint/CompositingDisplayItem.h
diff --git a/Source/platform/graphics/paint/CompositingDisplayItem.h b/Source/platform/graphics/paint/CompositingDisplayItem.h
index 251ff30a6707922bf38fd31288cfaab83ae5a5b8..9d826ed342ec342d51cdec529c43457e58567b1a 100644
--- a/Source/platform/graphics/paint/CompositingDisplayItem.h
+++ b/Source/platform/graphics/paint/CompositingDisplayItem.h
@@ -17,13 +17,7 @@
 namespace blink {
 
 class PLATFORM_EXPORT BeginCompositingDisplayItem : public PairedBeginDisplayItem {
-    WTF_MAKE_FAST_ALLOCATED(BeginCompositingDisplayItem);
 public:
-    static PassOwnPtr<BeginCompositingDisplayItem> create(const DisplayItemClientWrapper& client, const SkXfermode::Mode xferMode, const float opacity, const FloatRect* bounds = nullptr, ColorFilter colorFilter = ColorFilterNone)
-    {
-        return adoptPtr(new BeginCompositingDisplayItem(client, xferMode, opacity, bounds, colorFilter));
-    }
-
     BeginCompositingDisplayItem(const DisplayItemClientWrapper& client, const SkXfermode::Mode xferMode, const float opacity, const FloatRect* bounds, ColorFilter colorFilter = ColorFilterNone)
         : PairedBeginDisplayItem(client, BeginCompositing)
         , m_xferMode(xferMode)
@@ -37,6 +31,7 @@ public:
 
     virtual void replay(GraphicsContext&) override;
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override;
+    void appendByMoving(DisplayItems&) override;
 
 private:
 #ifndef NDEBUG
@@ -50,18 +45,13 @@ private:
 };
 
 class PLATFORM_EXPORT EndCompositingDisplayItem : public PairedEndDisplayItem {
-    WTF_MAKE_FAST_ALLOCATED(EndCompositingDisplayItem);
 public:
-    static PassOwnPtr<EndCompositingDisplayItem> create(const DisplayItemClientWrapper& client)
-    {
-        return adoptPtr(new EndCompositingDisplayItem(client));
-    }
-
     EndCompositingDisplayItem(const DisplayItemClientWrapper& client)
         : PairedEndDisplayItem(client, EndCompositing) { }
 
     virtual void replay(GraphicsContext&) override;
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override;
+    void appendByMoving(DisplayItems&) override;
 
 private:
 #if ENABLE(ASSERT)