TextAutosizer should handle cross-process navigation and RemoteFrame.

third_party/WebKit/Source/core/layout/TextAutosizer.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 513 matching lines @@
     } else {
         LayoutView* layoutView = m_document->layoutView();
         bool horizontalWritingMode = isHorizontalWritingMode(layoutView->style()->writingMode());
 
         // FIXME: With out-of-process iframes, the top frame can be remote and
         // doesn't have sizing information. Just return if this is the case.
         Frame* frame = m_document->frame()->tree().top();
         if (frame->isRemoteFrame())
             return;
 
-        LocalFrame* mainFrame = m_document->page()->deprecatedLocalMainFrame();
-        if (!mainFrame->view())
-            return;
-
+        LocalFrame* mainFrame = toLocalFrame(frame);
         IntSize frameSize = m_document->settings()->textAutosizingWindowSizeOverride();
         if (frameSize.isEmpty())
             frameSize = windowSize();
 
         m_pageInfo.m_frameWidth = horizontalWritingMode ? frameSize.width() : frameSize.height();
 
         IntSize layoutSize = mainFrame->view()->layoutSize();
         m_pageInfo.m_layoutWidth = horizontalWritingMode ? layoutSize.width() : layoutSize.height();
 
         // Compute the base font scale multiplier based on device and accessibility settings.
@@ skipping 636 matching lines @@
     }
     return computedSize;
 }
 
 DEFINE_TRACE(TextAutosizer)
 {
     visitor->trace(m_document);
 }
 
 } // namespace blink