Use the screen info's scale factor to scale the drag image

third_party/WebKit/Source/web/WebViewImpl.h

 /*
  * Copyright (C) 2010 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 194 matching lines @@
     void setMaximumLegibleScale(float) override;
     void setPageScaleFactor(float) override;
     void setVisualViewportOffset(const WebFloatPoint&) override;
     WebFloatPoint visualViewportOffset() const override;
     WebFloatSize visualViewportSize() const override;
     void resetScrollAndScaleState() override;
     void setIgnoreViewportTagScaleLimits(bool) override;
     WebSize contentsPreferredMinimumSize() override;
     void setDisplayMode(WebDisplayMode) override;
 
-    float deviceScaleFactor() const override;
     void setDeviceScaleFactor(float) override;
     void setZoomFactorForDeviceScaleFactor(float) override;
 
     void setDeviceColorProfile(const WebVector<char>&) override;
     void resetDeviceColorProfileForTesting() override;
 
     void enableAutoResizeMode(
         const WebSize& minSize,
         const WebSize& maxSize) override;
     void disableAutoResizeMode() override;
@@ skipping 395 matching lines @@
     WebInputEventResult handleSyntheticWheelFromTouchpadPinchEvent(const WebGestureEvent&);
 
     WebPlugin* focusedPluginIfInputMethodSupported(LocalFrame*);
 
     void enablePopupMouseWheelEventListener();
     void disablePopupMouseWheelEventListener();
 
     void cancelPagePopup();
     void updatePageOverlays();
 
+    float deviceScaleFactor() const;
+
     WebViewClient* m_client; // Can be 0 (e.g. unittests, shared workers, etc.)
     WebSpellCheckClient* m_spellCheckClient;
 
     OwnPtrWillBePersistent<ChromeClientImpl> m_chromeClientImpl;
     ContextMenuClientImpl m_contextMenuClientImpl;
     DragClientImpl m_dragClientImpl;
     EditorClientImpl m_editorClientImpl;
     SpellCheckerClientImpl m_spellCheckerClientImpl;
     StorageClientImpl m_storageClientImpl;
 
@@ skipping 134 matching lines @@
 };
 
 DEFINE_TYPE_CASTS(WebViewImpl, WebWidget, widget, widget->isWebView(), widget.isWebView());
 // We have no ways to check if the specified WebView is an instance of
 // WebViewImpl because WebViewImpl is the only implementation of WebView.
 DEFINE_TYPE_CASTS(WebViewImpl, WebView, webView, true, true);
 
 } // namespace blink
 
 #endif