refactor: use document.documentMode to determine msie version

src/Angular.js

@@ -171,13 +171,10 @@ var /** holds major version number for IE or NaN for real browsers */
     uid               = 0;
 
 /**
- * IE 11 changed the format of the UserAgent string.
- * See http://msdn.microsoft.com/en-us/library/ms537503.aspx
+ * documentMode is an IE-only property
+ * http://msdn.microsoft.com/en-us/library/ie/cc196988(v=vs.85).aspx
  */
-msie = int((/msie (\d+)/.exec(lowercase(navigator.userAgent)) || [])[1]);
-if (isNaN(msie)) {
-  msie = int((/trident\/.*; rv:(\d+)/.exec(lowercase(navigator.userAgent)) || [])[1]);
-}
+msie = document.documentMode;
 
 
 /**

src/ngScenario/browserTrigger.js

@@ -1,7 +1,11 @@
 'use strict';
 
 (function() {
-  var msie = parseInt((/msie (\d+)/.exec(navigator.userAgent.toLowerCase()) || [])[1], 10);
+  /**
+   * documentMode is an IE-only property
+   * http://msdn.microsoft.com/en-us/library/ie/cc196988(v=vs.85).aspx
+   */
+  msie = document.documentMode;
 
   /**
    * Triggers a browser event. Attempts to choose the right event if one is

test/jqLiteSpec.js

@@ -1185,7 +1185,8 @@ describe('jqLite', function() {
         if (window.jQuery) return;
         var browserMoveTrigger = function(from, to){
           var fireEvent = function(type, element, relatedTarget){
-            var evnt, msie = parseInt((/msie (\d+)/.exec(navigator.userAgent.toLowerCase()) || [])[1]);
+            var evnt;
+
             if (msie < 9){
               evnt = document.createEventObject();
               evnt.srcElement = element;

test/ngTouch/directive/ngSwipeSpec.js

@@ -14,14 +14,6 @@ var swipeTests = function(description, restrictBrowsers, startEvent, moveEvent,
       }
     }
 
-    // Skip tests on IE < 9. These versions of IE don't support createEvent(), and so
-    // we cannot control the (x,y) position of events.
-    // It works fine in IE 8 under manual testing.
-    var msie = +((/msie (\d+)/.exec(navigator.userAgent.toLowerCase()) || [])[1]);
-    if (msie < 9) {
-      return;
-    }
-
     beforeEach(function() {
       module('ngTouch');
     });

test/ngTouch/swipeSpec.js

@@ -4,14 +4,6 @@ describe('$swipe', function() {
   var element;
   var events;
 
-  // Skip tests on IE < 9. These versions of IE don't support createEvent(), and so
-  // we cannot control the (x,y) position of events.
-  // It works fine in IE 8 under manual testing.
-  var msie = +((/msie (\d+)/.exec(navigator.userAgent.toLowerCase()) || [])[1]);
-  if (msie < 9) {
-    return;
-  }
-
   beforeEach(function() {
     module('ngTouch');
     inject(function($compile, $rootScope) {