testPrefixedPropertyNameWebkitAndObject() {
    const mockDocument = {
      // setting a value of 0 on purpose, to ensure we only look for property
      // names, not their values.
      'webkitFoobar': 0,
    };
    assertUserAgent([UserAgents.WEBKIT], 'WebKit');
    assertEquals(
        'webkitFoobar', vendor.getPrefixedPropertyName('foobar', mockDocument));
  }
Tests for the prefixed property name on Webkit in an object.