Add DisplayItemListPictureRecorder

Source/core/layout/svg/LayoutSVGResourceClipper.cpp

Index: Source/core/layout/svg/LayoutSVGResourceClipper.cpp
diff --git a/Source/core/layout/svg/LayoutSVGResourceClipper.cpp b/Source/core/layout/svg/LayoutSVGResourceClipper.cpp
index abf1092c4b74cfc7473056648694d3e6efe4ffd7..5c5d07e700bf12c14120109533eaef2c0ab6415b 100644
--- a/Source/core/layout/svg/LayoutSVGResourceClipper.cpp
+++ b/Source/core/layout/svg/LayoutSVGResourceClipper.cpp
@@ -36,7 +36,7 @@
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/paint/ClipPathDisplayItem.h"
 #include "platform/graphics/paint/CompositingDisplayItem.h"
-#include "platform/graphics/paint/DisplayItemList.h"
+#include "platform/graphics/paint/DisplayItemListPictureRecorder.h"
 #include "platform/graphics/paint/DrawingDisplayItem.h"
 #include "third_party/skia/include/core/SkPicture.h"
 
@@ -154,11 +154,8 @@ PassRefPtr<const SkPicture> LayoutSVGResourceClipper::createContentPicture(Affin
     // userSpaceOnUse units (http://crbug.com/294900).
     FloatRect bounds = strokeBoundingBox();
 
-    OwnPtr<DisplayItemList> displayItemList;
-    if (RuntimeEnabledFeatures::slimmingPaintEnabled())
-        displayItemList = DisplayItemList::create();
-    GraphicsContext context(nullptr, displayItemList.get());
-    context.beginRecording(bounds);
+    DisplayItemListPictureRecorder pictureRecorder(bounds);

[chrishtr, 2015/03/31 21:52:51]

This is getting a little out of hand with lots of RAII variants. Is there no way
to encode such simple code into something without a new class?

+    GraphicsContext& context = pictureRecorder.context();
 
     for (SVGElement* childElement = Traversal<SVGElement>::firstChild(*element()); childElement; childElement = Traversal<SVGElement>::nextSibling(*childElement)) {
         LayoutObject* layoutObject = childElement->layoutObject();
@@ -198,9 +195,7 @@ PassRefPtr<const SkPicture> LayoutSVGResourceClipper::createContentPicture(Affin
         layoutObject->paint(info, IntPoint());
     }
 
-    if (displayItemList)
-        displayItemList->replay(&context);
-    m_clipContentPicture = context.endRecording();
+    m_clipContentPicture = pictureRecorder.endRecording();
     return m_clipContentPicture;
 }