Change Page::m_mainFrame to be a Frame.

Source/core/frame/PinchViewport.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 295 matching lines @@
     scrollbarGraphicsLayer->setPosition(IntPoint(xPosition, yPosition));
     scrollbarGraphicsLayer->setSize(IntSize(width, height));
     scrollbarGraphicsLayer->setContentsRect(IntRect(0, 0, width, height));
 }
 
 void PinchViewport::registerLayersWithTreeView(WebLayerTreeView* layerTreeView) const
 {
     TRACE_EVENT0("webkit", "PinchViewport::registerLayersWithTreeView");
     ASSERT(layerTreeView);
     ASSERT(m_frameHost.page().mainFrame());
-    ASSERT(m_frameHost.page().mainFrame()->contentRenderer());
+    ASSERT(m_frameHost.page().mainFrame()->isLocalFrame());
+    ASSERT(m_frameHost.page().deprecatedLocalMainFrame()->contentRenderer());
 
-    RenderLayerCompositor* compositor = m_frameHost.page().mainFrame()->contentRenderer()->compositor();
+    RenderLayerCompositor* compositor = m_frameHost.page().deprecatedLocalMainFrame()->contentRenderer()->compositor();
     // Get the outer viewport scroll layer.
     WebLayer* scrollLayer = compositor->scrollLayer()->platformLayer();
 
     m_webOverlayScrollbarHorizontal->setScrollLayer(scrollLayer);
     m_webOverlayScrollbarVertical->setScrollLayer(scrollLayer);
 
     ASSERT(compositor);
     layerTreeView->registerViewportLayers(
         m_pageScaleLayer->platformLayer(),
         m_innerViewportScrollLayer->platformLayer(),
@@ skipping 82 matching lines @@
 void PinchViewport::notifyAnimationStarted(const GraphicsLayer*, double monotonicTime)
 {
 }
 
 void PinchViewport::paintContents(const GraphicsLayer*, GraphicsContext&, GraphicsLayerPaintingPhase, const IntRect& inClip)
 {
 }
 
 LocalFrame* PinchViewport::mainFrame() const
 {
-    return m_frameHost.page().mainFrame();
+    return m_frameHost.page().mainFrame() && m_frameHost.page().mainFrame()->isLocalFrame() ? m_frameHost.page().deprecatedLocalMainFrame() : 0;
 }
 
 FloatPoint PinchViewport::clampOffsetToBoundaries(const FloatPoint& offset)
 {
     FloatPoint clampedOffset(offset);
     clampedOffset = clampedOffset.shrunkTo(FloatPoint(maximumScrollPosition()));
     clampedOffset = clampedOffset.expandedTo(FloatPoint(minimumScrollPosition()));
     return clampedOffset;
 }
 
@@ skipping 11 matching lines @@
     } else if (graphicsLayer == m_overlayScrollbarVertical.get()) {
         name =  "Overlay Scrollbar Vertical Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore