DevTools: only set title w/ shortcut via Tooltip manager API.

Source/devtools/front_end/emulation/OverridesView.js

 /*
  * Copyright (C) 2014 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 207 matching lines @@
         var widthOverrideInput = WebInspector.SettingsUI.createSettingInputField("", WebInspector.overridesSupport.settings.deviceWidth, true, 4, "80px", WebInspector.OverridesSupport.deviceSizeValidator, true, true, WebInspector.UIString("\u2013"));
         cellElement.appendChild(widthOverrideInput);
         var heightOverrideInput = WebInspector.SettingsUI.createSettingInputField("", WebInspector.overridesSupport.settings.deviceHeight, true, 4, "80px", WebInspector.OverridesSupport.deviceSizeValidator, true, true, WebInspector.UIString("\u2013"));
         cellElement.appendChild(heightOverrideInput);
 
         rowElement = tableElement.createChild("tr");
         cellElement = rowElement.createChild("td");
         cellElement.colSpan = 4;
 
         rowElement = tableElement.createChild("tr");
-        WebInspector.Tooltip.install(rowElement, WebInspector.UIString("Ratio between a device's physical pixels and device-independent pixels"));
+        rowElement.title = WebInspector.UIString("Ratio between a device's physical pixels and device-independent pixels");
         rowElement.createChild("td").createTextChild(WebInspector.UIString("Device pixel ratio:"));
         rowElement.createChild("td").appendChild(WebInspector.SettingsUI.createSettingInputField("", WebInspector.overridesSupport.settings.deviceScaleFactor, true, 4, "80px", WebInspector.OverridesSupport.deviceScaleFactorValidator, true, true, WebInspector.UIString("\u2013")));
 
         var mobileCheckbox = this._createSettingCheckbox(WebInspector.UIString("Emulate mobile"), WebInspector.overridesSupport.settings.emulateMobile);
-        WebInspector.Tooltip.install(mobileCheckbox, WebInspector.UIString("Enable meta viewport, overlay scrollbars, text autosizing and default 980px body width"));
+        mobileCheckbox.title = WebInspector.UIString("Enable meta viewport, overlay scrollbars, text autosizing and default 980px body width");
         fieldsetElement.appendChild(mobileCheckbox);
 
         fieldsetElement.appendChild(this._createSettingCheckbox(WebInspector.UIString("Shrink to fit"), WebInspector.overridesSupport.settings.deviceFitWindow));
 
         return fieldsetElement;
     },
 
     __proto__: WebInspector.OverridesView.Tab.prototype
 }
 
@@ skipping 371 matching lines @@
      * @override
      * @param {!Object} overridesSupport
      * @return {!Promise}
      */
     reveal: function(overridesSupport)
     {
         WebInspector.inspectorView.showViewInDrawer("emulation");
         return Promise.resolve();
     }
 }