revert: fix(ngMock): attach $injector to $rootElement

This reverts commit 88bb551.

The fixes applied in the reverted commit caused a memory leak
with JQuery + Karma.

Author: matsko

src/ngMock/angular-mocks.js

@@ -2090,9 +2090,9 @@ angular.mock.$RAFDecorator = ['$delegate', function($delegate) {
  *
  */
 angular.mock.$RootElementProvider = function() {
-  this.$get = ['$injector', function($injector) {
-    return angular.element('<div ng-app></div>').data('$injector', $injector);
-  }];
+  this.$get = function() {
+    return angular.element('<div ng-app></div>');
+  };
 };
 
 /**

test/ngMock/angular-mocksSpec.js

@@ -1667,10 +1667,6 @@ describe('ngMock', function() {
     it('should create mock application root', inject(function($rootElement) {
       expect($rootElement.text()).toEqual('');
     }));
-
-    it('should attach the `$injector` to `$rootElement`', inject(function($injector, $rootElement) {
-      expect($rootElement.injector()).toBe($injector);
-    }));
   });