[cc] Store CCLayerImpls as scoped_ptrs

cc/ScrollbarLayerChromium.cpp

 // Copyright 2012 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.
 
 #include "config.h"
 
 #if USE(ACCELERATED_COMPOSITING)
 
 #include "ScrollbarLayerChromium.h"
 
 #include "base/basictypes.h"
 #include "CCLayerTreeHost.h"
 #include "CCScrollbarLayerImpl.h"
 #include "CCTextureUpdateQueue.h"
 #include "LayerPainterChromium.h"
 #include "TraceEvent.h"
 #include <public/WebRect.h>
 
 using WebKit::WebRect;
 
 namespace cc {
 
-PassOwnPtr<CCLayerImpl> ScrollbarLayerChromium::createCCLayerImpl()
+scoped_ptr<CCLayerImpl> ScrollbarLayerChromium::createCCLayerImpl()
 {
-    return CCScrollbarLayerImpl::create(id());
+    return CCScrollbarLayerImpl::create(id()).PassAs<CCLayerImpl>();
 }
 
 scoped_refptr<ScrollbarLayerChromium> ScrollbarLayerChromium::create(PassOwnPtr<WebKit::WebScrollbar> scrollbar, WebKit::WebScrollbarThemePainter painter, PassOwnPtr<WebKit::WebScrollbarThemeGeometry> geometry, int scrollLayerId)
 {
     return make_scoped_refptr(new ScrollbarLayerChromium(scrollbar, painter, geometry, scrollLayerId));
 }
 
 ScrollbarLayerChromium::ScrollbarLayerChromium(PassOwnPtr<WebKit::WebScrollbar> scrollbar, WebKit::WebScrollbarThemePainter painter, PassOwnPtr<WebKit::WebScrollbarThemeGeometry> geometry, int scrollLayerId)
     : m_scrollbar(scrollbar)
     , m_painter(painter)
@@ skipping 247 matching lines @@
 
     // Consider the thumb to be at the origin when painting.
     WebKit::WebRect thumbRect = m_geometry->thumbRect(m_scrollbar.get());
     IntRect originThumbRect = layerRectToContentRect(WebKit::WebRect(0, 0, thumbRect.width, thumbRect.height));
     if (!originThumbRect.isEmpty())
         updatePart(m_thumbUpdater.get(), m_thumb.get(), originThumbRect, queue, stats);
 }
 
 }
 #endif // USE(ACCELERATED_COMPOSITING)