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

Source/devtools/front_end/Settings.js

 /*
  * Copyright (C) 2009 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 61 matching lines @@
     this.domBreakpoints = this.createSetting("domBreakpoints", []);
     this.xhrBreakpoints = this.createSetting("xhrBreakpoints", []);
     this.jsSourceMapsEnabled = this.createSetting("sourceMapsEnabled", true);
     this.cssSourceMapsEnabled = this.createSetting("cssSourceMapsEnabled", true);
     this.cacheDisabled = this.createSetting("cacheDisabled", false);
     this.overrideUserAgent = this.createSetting("overrideUserAgent", false);
     this.userAgent = this.createSetting("userAgent", "");
     this.overrideDeviceMetrics = this.createSetting("overrideDeviceMetrics", false);
     this.deviceMetrics = this.createSetting("deviceMetrics", "");
     this.deviceFitWindow = this.createSetting("deviceFitWindow", true);
+    this.emulateViewport = this.createSetting("emulateViewport", false);
     this.emulateTouchEvents = this.createSetting("emulateTouchEvents", false);
     this.showShadowDOM = this.createSetting("showShadowDOM", false);
     this.zoomLevel = this.createSetting("zoomLevel", 0);
     this.savedURLs = this.createSetting("savedURLs", {});
     this.javaScriptDisabled = this.createSetting("javaScriptDisabled", false);
     this.overrideGeolocation = this.createSetting("overrideGeolocation", false);
     this.geolocationOverride = this.createSetting("geolocationOverride", "");
     this.overrideDeviceOrientation = this.createSetting("overrideDeviceOrientation", false);
     this.deviceOrientationOverride = this.createSetting("deviceOrientationOverride", "");
     this.showAdvancedHeapSnapshotProperties = this.createSetting("showAdvancedHeapSnapshotProperties", false);
@@ skipping 378 matching lines @@
     {
         // If there are too many breakpoints in a storage, it is likely due to a recent bug that caused
         // periodical breakpoints duplication leading to inspector slowness.
         if (breakpointsSetting.get().length > maxBreakpointsCount)
             breakpointsSetting.set([]);
     }
 }
 
 WebInspector.settings = new WebInspector.Settings();
 WebInspector.experimentsSettings = new WebInspector.ExperimentsSettings();