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

Source/platform/graphics/paint/FilterDisplayItem.h

Index: Source/platform/graphics/paint/FilterDisplayItem.h
diff --git a/Source/platform/graphics/paint/FilterDisplayItem.h b/Source/platform/graphics/paint/FilterDisplayItem.h
index 549938edb3b21e503b5897c8077406360ce98987..271487ad7da8329c7172536105b3b387ae563552 100644
--- a/Source/platform/graphics/paint/FilterDisplayItem.h
+++ b/Source/platform/graphics/paint/FilterDisplayItem.h
@@ -31,12 +31,13 @@ public:
 
     virtual void replay(GraphicsContext&) override;
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override;
+    virtual void appendByMoving(DisplayItems&) override;
     virtual bool drawsContent() const override;
 
-private:
     BeginFilterDisplayItem(const DisplayItemClientWrapper&, PassRefPtr<SkImageFilter>, const FloatRect& bounds);
     BeginFilterDisplayItem(const DisplayItemClientWrapper&, PassRefPtr<SkImageFilter>, const FloatRect& bounds, PassOwnPtr<WebFilterOperations>);
 
+private:
 #ifndef NDEBUG
     virtual void dumpPropertiesAsDebugString(WTF::StringBuilder&) const override;
 #endif
@@ -60,6 +61,7 @@ public:
 
     virtual void replay(GraphicsContext&) override;
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override;
+    virtual void appendByMoving(DisplayItems&) override;
 
 private:
 #if ENABLE(ASSERT)