Use refs for GraphicsContext

third_party/WebKit/Source/platform/graphics/paint/SkPictureBuilder.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SkPictureBuilder_h
 #define SkPictureBuilder_h
 
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/paint/PaintController.h"
 #include "wtf/Allocator.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/OwnPtr.h"
 
 namespace blink {
 
 // When slimming paint ships we can remove this SkPicture abstraction and
 // rely on PaintController here.
 class SkPictureBuilder final {
     WTF_MAKE_NONCOPYABLE(SkPictureBuilder);
     STACK_ALLOCATED();
 public:
-    SkPictureBuilder(const FloatRect& bounds, SkMetaData* metaData = 0, GraphicsContext* containingContext = 0)
+    SkPictureBuilder(const FloatRect& bounds, SkMetaData* metaData = nullptr, GraphicsContext* containingContext = nullptr)
         : m_bounds(bounds)
     {
         GraphicsContext::DisabledMode disabledMode = GraphicsContext::NothingDisabled;
         if (containingContext && containingContext->contextDisabled())
             disabledMode = GraphicsContext::FullyDisabled;
 
         m_paintController = PaintController::create();
         m_paintController->beginSkippingCache();
         m_context = adoptPtr(new GraphicsContext(*m_paintController, disabledMode, metaData));
 
@@ skipping 16 matching lines @@
 
 private:
     OwnPtr<PaintController> m_paintController;
     OwnPtr<GraphicsContext> m_context;
     FloatRect m_bounds;
 };
 
 } // namespace blink
 
 #endif // SkPictureBuilder_h