Revert 160631 - [cc] Store CCLayerImpls as scoped_ptrs

cc/LayerChromium.h

Index: cc/LayerChromium.h
===================================================================
--- cc/LayerChromium.h	(revision 160631)
+++ cc/LayerChromium.h	(working copy)
@@ -11,6 +11,7 @@
 #include "base/memory/ref_counted.h"
 #include "CCLayerAnimationController.h"
 #include "CCOcclusionTracker.h"
+#include "CCPrioritizedTexture.h"
 #include "FloatPoint.h"
 #include "Region.h"
 #include "RenderSurfaceChromium.h"
@@ -19,6 +20,8 @@
 #include <public/WebTransformationMatrix.h>
 #include <string>
 #include <vector>
+#include <wtf/OwnPtr.h>
+#include <wtf/PassOwnPtr.h>
 
 namespace WebKit {
 class WebAnimationDelegate;
@@ -32,7 +35,6 @@
 class CCLayerAnimationDelegate;
 class CCLayerImpl;
 class CCLayerTreeHost;
-class CCPriorityCalculator;
 class CCTextureUpdateQueue;
 class ScrollbarLayerChromium;
 struct CCAnimationEvent;
@@ -289,7 +291,7 @@
     scoped_refptr<LayerChromium> m_maskLayer;
 
     // Constructs a CCLayerImpl of the correct runtime type for this LayerChromium type.
-    virtual scoped_ptr<CCLayerImpl> createCCLayerImpl();
+    virtual PassOwnPtr<CCLayerImpl> createCCLayerImpl();
     int m_layerId;
 
 private: