[Tooltip] Changed the way the tooltip functions to make up for the fa…

…ct firefox doesn't have certain properties on the event and event target

better offset

src/kibana/components/vislib/visualizations/_point_series_chart.js

@@ -48,6 +48,7 @@ define(function (require) {
      * @returns {D3.Selection}
      */
     PointSeriesChart.prototype.createEndZones = function (svg) {
+      var self = this;
       var xAxis = this.handler.xAxis;
       var xScale = xAxis.xScale;
       var yScale = xAxis.yScale;
@@ -100,19 +101,22 @@ define(function (require) {
 
       function callPlay(event) {
         var boundData = event.target.__data__;
+        var offsetX = self.chartEl.getBoundingClientRect().left;
         var wholeBucket = boundData && boundData.x != null;
 
+        // the min and max that the endzones start in
         var min = leftEndzone.w;
         var max = rightEndzone.x;
 
         // bounds of the cursor to consider
-        var xLeft = event.offsetX;
-        var xRight = event.offsetX;
+        var xLeft = event.clientX - offsetX;
+        var xRight = event.clientX - offsetX;
         if (wholeBucket) {
           xLeft = xScale(boundData.x);
           xRight = xScale(xAxis.addInterval(boundData.x));
         }
 
+
         return {
           wholeBucket: wholeBucket,
           touchdown: min > xLeft || max < xRight
@@ -133,4 +137,4 @@ define(function (require) {
 
     return PointSeriesChart;
   };
-});
+});