Cross-process frames should be notified of device scale factor changes.

content/renderer/render_view_impl.cc

 // Copyright (c) 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 "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <memory>
 
@@ skipping 1314 matching lines @@
                         OnSetHistoryOffsetAndLength)
     IPC_MESSAGE_HANDLER(ViewMsg_ReleaseDisambiguationPopupBitmap,
                         OnReleaseDisambiguationPopupBitmap)
     IPC_MESSAGE_HANDLER(ViewMsg_ForceRedraw, OnForceRedraw)
     IPC_MESSAGE_HANDLER(ViewMsg_SelectWordAroundCaret, OnSelectWordAroundCaret)
 
     // Page messages.
     IPC_MESSAGE_HANDLER(PageMsg_UpdateWindowScreenRect,
                         OnUpdateWindowScreenRect)
     IPC_MESSAGE_HANDLER(PageMsg_SetZoomLevel, OnSetZoomLevel)
+    IPC_MESSAGE_HANDLER(PageMsg_SetDeviceScaleFactor, OnSetDeviceScaleFactor);
     IPC_MESSAGE_HANDLER(PageMsg_WasHidden, OnPageWasHidden)
     IPC_MESSAGE_HANDLER(PageMsg_WasShown, OnPageWasShown)
 
 #if defined(OS_ANDROID)
     IPC_MESSAGE_HANDLER(ViewMsg_UpdateTopControlsState,
                         OnUpdateTopControlsState)
     IPC_MESSAGE_HANDLER(ViewMsg_ExtractSmartClipData, OnExtractSmartClipData)
 #elif defined(OS_MACOSX)
     IPC_MESSAGE_HANDLER(ViewMsg_GetRenderedText,
                         OnGetRenderedText)
@@ skipping 1733 matching lines @@
         return render_frame->focused_pepper_plugin();
     }
     frame = frame->traverseNext(false);
   }
 
   return nullptr;
 }
 #endif
 
 }  // namespace content