Testing AngularJS Service - mocking $rootElement and $rootScope

I am currently writing some tests for a service that updates the meta information on a page.

mod.service('MetaSrv', ['$rootScope', '$rootElement', function ($rootScope, $rootElement){

return {
    updateMetaTitle: function(contents) {
        $rootScope.metaTitle = contents;
    },
    updateMetaElement: function(type, contents) {
        var metaEl = angular.element($rootElement.find('meta[name="'+ type +'"]')[0]);
        metaEl.attr('content', contents);
    }
};
}]);

I want to test each of these functions as a starting point. The tests look like this:

describe('sets', function() {

    it('meta title element using $rootscope', function() {
        MetaSrv.updateMetaTitle('Some Title');
        expect(scope.metaTitle).toBe('Some Title');
    });

    it('meta description element using $rootElement', function() {
        MetaSrv.updateMetaElement('description', 'Some Description');
        var el = angular.element(rootElement.find('meta[name="description"]')[0]);
        expect(el.attr('content')).toBe('Some Description');
    });
});

I need to be able to use $rootScope for the first tests and then will need access to $rootElement for the second two tests. The describe block is as follows:

var MetaSrv, scope, rootElement, element;

beforeEach(function() {

    module('mod');

    inject(function (_MetaSrv_, $rootScope, $rootElement) {
        MetaSrv = _MetaSrv_;
        scope = $rootScope.$new();
        rootElement = $rootElement;
    });
});

Currently the first test works fine. The second two tests that use $rootElement are not working correctly, it cannot find the meta tags on $rootElement. I am not sure how to mock $rootElement dependancy in order to test the meta information change.