fix(slider): vertical slider in a scrolled container sets value to zero on all clicks (#11801)

Fixes #11800

Author: Thaina

src/components/slider/slider.js

@@ -561,7 +561,7 @@ function SliderDirective($$rAF, $window, $mdAria, $mdUtil, $mdConstant, $mdThemi
       element[0].focus();
       refreshSliderDimensions();
 
-      var exactVal = percentToValue(positionToPercent(vertical ? ev.pointer.y : ev.pointer.x));
+      var exactVal = percentToValue(positionToPercent(vertical ? ev.srcEvent.clientY : ev.srcEvent.clientX));
       var closestVal = minMaxValidator(stepValidator(exactVal));
       scope.$apply(function() {
         setModelValue(closestVal);
@@ -573,7 +573,7 @@ function SliderDirective($$rAF, $window, $mdAria, $mdUtil, $mdConstant, $mdThemi
 
       element.removeClass('md-dragging');
 
-      var exactVal = percentToValue(positionToPercent(vertical ? ev.pointer.y : ev.pointer.x));
+      var exactVal = percentToValue(positionToPercent(vertical ? ev.srcEvent.clientY : ev.srcEvent.clientX));
       var closestVal = minMaxValidator(stepValidator(exactVal));
       scope.$apply(function() {
         setModelValue(closestVal);
@@ -603,8 +603,8 @@ function SliderDirective($$rAF, $window, $mdAria, $mdUtil, $mdConstant, $mdThemi
     function setSliderFromEvent(ev) {
       // While panning discrete, update only the
       // visual positioning but not the model value.
-      if (discrete) adjustThumbPosition(vertical ? ev.pointer.y : ev.pointer.x);
-      else            doSlide(vertical ? ev.pointer.y : ev.pointer.x);
+      if (discrete) adjustThumbPosition(vertical ? ev.srcEvent.clientY : ev.srcEvent.clientX);
+      else            doSlide(vertical ? ev.srcEvent.clientY : ev.srcEvent.clientX);
     }
 
     /**