@Override
            public void onPostMessageServiceDisconnected() {
                mPostMessageServiceConnected = false;
            }
Tests for a complete loop between a browser side {@link CustomTabsService}
and a client side {@link PostMessageService}. Both services are bound to through
{@link ServiceTestRule}, but {@link CustomTabsCallback#extraCallback} is used to link browser
side actions.
customtabs/tests/src/android/support/customtabs/PostMessageTest.java