DevTools: [MQI] add tooltips for ruler serifs

Source/devtools/front_end/toolbox/MediaQueryInspector.js

Index: Source/devtools/front_end/toolbox/MediaQueryInspector.js
diff --git a/Source/devtools/front_end/toolbox/MediaQueryInspector.js b/Source/devtools/front_end/toolbox/MediaQueryInspector.js
index 0127465d399d4968b83ebc4bb9145150db61a9fa..5793baed2b58f616f4ba201e19c579799882d31a 100644
--- a/Source/devtools/front_end/toolbox/MediaQueryInspector.js
+++ b/Source/devtools/front_end/toolbox/MediaQueryInspector.js
@@ -357,6 +357,7 @@ WebInspector.MediaQueryInspector.prototype = {
         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";
         }