Pass ui::LatencyInfo correct with unified gesture detector on Aura.

BUG=379812
TEST=GestureRecognizerTest.LatencyPassedFromTouchEvent

Review URL: https://codereview.chromium.org/309823002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274602 0039d316-1c4b-4281-b951-d872f2087c98
  base::TimeDelta Now() {
    base::TimeDelta t = base::TimeDelta::FromMilliseconds(simulated_now_);
    simulated_now_++;
    return t;
  }

  base::TimeDelta Now() {
    base::TimeDelta t = base::TimeDelta::FromMilliseconds(simulated_now_);
    simulated_now_++;
    return t;
  }
