DevTools: explicitly control support for viewport meta tag so that desktop emulation was possible

Source/web/WebDevToolsAgentImpl.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 85 matching lines @@
 
     // InspectorClient implementation.
     virtual void highlight();
     virtual void hideHighlight();
     virtual void updateInspectorStateCookie(const WTF::String&);
     virtual bool sendMessageToFrontend(const WTF::String&);
 
     virtual void clearBrowserCache();
     virtual void clearBrowserCookies();
 
-    virtual void overrideDeviceMetrics(int width, int height, float deviceScaleFactor, bool fitWindow);
+    virtual void overrideDeviceMetrics(int width, int height, float deviceScaleFactor, bool emulateViewport, bool fitWindow);
 
     virtual void getAllocatedObjects(HashSet<const void*>&);
     virtual void dumpUncountedAllocatedObjects(const HashMap<const void*, size_t>&);
     virtual void setTraceEventCallback(TraceEventCallback);
 
     virtual void dispatchKeyEvent(const WebCore::PlatformKeyboardEvent&);
     virtual void dispatchMouseEvent(const WebCore::PlatformMouseEvent&);
 
     int hostId() { return m_hostId; }
 
     // WebPageOverlay
     virtual void paintPageOverlay(WebCanvas*);
 
     virtual WebSize deviceMetricsOffset() OVERRIDE;
 
 private:
     // WebThread::TaskObserver
     virtual void willProcessTask();
     virtual void didProcessTask();
 
+    void enableViewportEmulation();
+    void disableViewportEmulation();
+
     WebCore::InspectorController* inspectorController();
     WebCore::Frame* mainFrame();
 
     int m_hostId;
     WebDevToolsAgentClient* m_client;
     WebViewImpl* m_webViewImpl;
     bool m_attached;
     bool m_generatingEvent;
     bool m_deviceMetricsEnabled;
+    bool m_emulateViewportEnabled;
+    bool m_originalViewportEnabled;
     bool m_isOverlayScrollbarsEnabled;
-    bool m_isCSSViewportEnabled;
 };
 
 } // namespace WebKit
 
 #endif