Blink-side contiguous allocation of display items.

Source/core/paint/SVGMaskPainter.cpp

Index: Source/core/paint/SVGMaskPainter.cpp
diff --git a/Source/core/paint/SVGMaskPainter.cpp b/Source/core/paint/SVGMaskPainter.cpp
index 6f6bbac23d50e381758671b12ab62eecda455897..13b9183bbfa0b963eab30c88d3f5f2d87b51e569 100644
--- a/Source/core/paint/SVGMaskPainter.cpp
+++ b/Source/core/paint/SVGMaskPainter.cpp
@@ -32,7 +32,7 @@ bool SVGMaskPainter::prepareEffect(const LayoutObject& object, GraphicsContext*
         ASSERT(context->displayItemList());
         if (context->displayItemList()->displayItemConstructionIsDisabled())
             return true;
-        context->displayItemList()->add(BeginCompositingDisplayItem::create(object, SkXfermode::kSrcOver_Mode, 1, &paintInvalidationRect));
+        context->displayItemList()->createAndAppendIfNeeded<BeginCompositingDisplayItem>(object, SkXfermode::kSrcOver_Mode, 1, &paintInvalidationRect);
     } else {
         BeginCompositingDisplayItem beginCompositingContent(object, SkXfermode::kSrcOver_Mode, 1, &paintInvalidationRect);
         beginCompositingContent.replay(*context);
@@ -59,7 +59,7 @@ void SVGMaskPainter::finishEffect(const LayoutObject& object, GraphicsContext* c
         ASSERT(context->displayItemList());
         if (context->displayItemList()->displayItemConstructionIsDisabled())
             return;
-        context->displayItemList()->add(EndCompositingDisplayItem::create(object));
+        context->displayItemList()->createAndAppendIfNeeded<EndCompositingDisplayItem>(object);
     } else {
         EndCompositingDisplayItem endCompositingContent(object);
         endCompositingContent.replay(*context);