Introduce painted-device-scale-factor and use it when --enable-use-zoom-for-dsf is specified.

third_party/WebKit/Source/web/WebPagePopupImpl.cpp

 /*
  * Copyright (C) 2012 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 327 matching lines @@
     } else if (m_layerTreeView) {
         m_isAcceleratedCompositingActive = true;
     } else {
         TRACE_EVENT0("blink", "WebPagePopupImpl::setIsAcceleratedCompositingActive(true)");
 
         m_widgetClient->initializeLayerTreeView();
         m_layerTreeView = m_widgetClient->layerTreeView();
         if (m_layerTreeView) {
             m_layerTreeView->setVisible(true);
             m_isAcceleratedCompositingActive = true;
-            m_layerTreeView->setDeviceScaleFactor(m_widgetClient->deviceScaleFactor());
+            m_layerTreeView->setDeviceScaleFactor(m_webView->deviceScaleFactor());
         } else {
             m_isAcceleratedCompositingActive = false;
         }
     }
 }
 
 WebSize WebPagePopupImpl::size()
 {
     return m_popupClient->contentSize();
 }
@@ skipping 180 matching lines @@
     // A WebPagePopupImpl instance usually has two references.
     //  - One owned by the instance itself. It represents the visible widget.
     //  - One owned by a WebViewImpl. It's released when the WebViewImpl ask the
     //    WebPagePopupImpl to close.
     // We need them because the closing operation is asynchronous and the widget
     // can be closed while the WebViewImpl is unaware of it.
     return adoptRef(new WebPagePopupImpl(client)).leakRef();
 }
 
 } // namespace blink