DevTools: [MQI] add tooltips for ruler serifs

Source/devtools/front_end/toolbox/MediaQueryInspector.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @constructor
  * @extends {WebInspector.View}
  * @implements {WebInspector.TargetManager.Observer}
  */
 WebInspector.MediaQueryInspector = function()
@@ skipping 339 matching lines @@
     },
 
     _renderRulerDecorations: function()
     {
         this._rulerDecorationLayer.removeChildren();
         var zoomFactor = this._zoomFactor();
 
         var thresholds = this._mediaQueryThresholds();
         for (var i = 0; i < thresholds.length; ++i) {
             var thresholdElement = this._rulerDecorationLayer.createChild("div", "media-inspector-threshold-serif");
+            thresholdElement.title = thresholds[i] + "px";

[dgozman, 2014/08/16 17:54:13]

Do you think we should round the value?

[lushnikov, 2014/08/16 18:18:52]

They are integers - no need for conversion here.

             thresholdElement._value = thresholds[i];
             thresholdElement.style.left = (thresholds[i] - this._offset) / zoomFactor + "px";
         }
     },
 
     wasShown: function()
     {
         this._renderMediaQueries();
     },
 
@@ skipping 177 matching lines @@
     },
 
     /**
      * @return {?WebInspector.CSSMediaQueryExpression}
      */
     maxWidthExpression: function()
     {
         return this._maxWidthExpression;
     }
 }