fix($$RAFProvider): check for webkitCancelRequestAnimationFrame

Android 4.3 only supports webkitCancelRequestAnimationFrame.

Closes angular#6526

Author: Traxmaxx

src/ng/raf.js

@@ -8,7 +8,8 @@ function $$RAFProvider(){ //rAF
 
     var cancelAnimationFrame = $window.cancelAnimationFrame ||
                                $window.webkitCancelAnimationFrame ||
-                               $window.mozCancelAnimationFrame;
+                               $window.mozCancelAnimationFrame ||
+                               $window.webkitCancelRequestAnimationFrame;
 
     var rafSupported = !!requestAnimationFrame;
     var raf = rafSupported

test/ng/rafSpec.js

@@ -76,4 +76,31 @@ describe('$$rAF', function() {
       }
     }));
   });
+
+  describe('mobile', function() {
+    it('should provide a cancellation method for an older version of Android', function() {
+
+      //we need to create our own injector to work around the ngMock overrides
+      var injector = createInjector(['ng', function($provide) {
+        $provide.decorator('$window', function($delegate) {
+          $delegate.requestAnimationFrame = noop;
+          $delegate.cancelAnimationFrame = false;
+          $delegate.webkitCancelAnimationFrame = false;
+          $delegate.mozCancelAnimationFrame = false;
+          $delegate.webkitCancelRequestAnimationFrame = jasmine.createSpy();
+          return $delegate;
+        });
+      }]);
+
+      var $$rAF = injector.get('$$rAF');
+      var $window = injector.get('$window');
+      var cancel = $$rAF(function() {});
+
+      try {
+        cancel();
+      } catch(e) {}
+
+      expect($window.webkitCancelRequestAnimationFrame).toHaveBeenCalled();
+    });
+  });
 });