fix(datepicker): remove dependency on $mdGesture (#9803)

Removes the datepicker's dependency on `$mdGesture` by inlining the check. This is a preparation for the switch over to HammerJS.

Fixes #9793.

Author: crisbeto

src/components/datepicker/js/datepickerDirective.js

@@ -218,13 +218,16 @@
    */
   var CALENDAR_PANE_WIDTH = 360;
 
+  /** Used for checking whether the current user agent is on iOS or Android. */
+  var IS_MOBILE_REGEX = /ipad|iphone|ipod|android/i;
+
   /**
    * Controller for md-datepicker.
    *
    * @ngInject @constructor
    */
   function DatePickerCtrl($scope, $element, $attrs, $window, $mdConstant,
-    $mdTheming, $mdUtil, $mdDateLocale, $$mdDateUtil, $$rAF, $mdGesture, $filter) {
+    $mdTheming, $mdUtil, $mdDateLocale, $$mdDateUtil, $$rAF, $filter) {
 
     /** @final */
     this.$window = $window;
@@ -323,7 +326,9 @@
      * the resize event doesn't make sense on mobile and can have a negative impact since it
      * triggers whenever the browser zooms in on a focused input.
      */
-    this.windowEventName = ($mdGesture.isIos || $mdGesture.isAndroid) ? 'orientationchange' : 'resize';
+    this.windowEventName = IS_MOBILE_REGEX.test(
+      navigator.userAgent || navigator.vendor || window.opera
+    ) ? 'orientationchange' : 'resize';
 
     /** Pre-bound close handler so that the event listener can be removed. */
     this.windowEventHandler = $mdUtil.debounce(angular.bind(this, this.closeCalendarPane), 100);

src/core/services/gesture/gesture.js

@@ -79,8 +79,6 @@ function MdGesture($$MdGestureHandler, $$rAF, $timeout) {
   var self = {
     handler: addHandler,
     register: register,
-    isIos: isIos,
-    isAndroid: isAndroid,
     // On mobile w/out jQuery, we normally intercept clicks. Should we skip that?
     isHijackingClicks: (isIos || isAndroid) && !hasJQuery && !forceSkipClickHijack
   };