@Override
    protected void finished(Description description) {
        if (mContext != null && mSession != null) {
            try {
                mContext.unbindService(mConnection);
            } catch (RuntimeException e) {} // Service might be disabled at this point
        }
    }
Binds the CustomTabsService, creates a {@link CustomTabsSession} and returns it.
customtabs/tests/src/android/support/customtabs/testutil/CustomTabConnectionRule.java