Delete unneeded pending entries in DidFailProvisionalLoad to prevent a spoof.

BUG=280512
BUG=278899
TEST=See bug for repro steps.

Review URL: https://chromiumcodereview.appspot.com/23978003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222146 0039d316-1c4b-4281-b951-d872f2087c98
base::Time NavigationControllerImpl::TimeSmoother::GetSmoothedTime(
    base::Time t) {
  if (low_water_mark_ <= t && t <= high_water_mark_) {
    high_water_mark_ += base::TimeDelta::FromMicroseconds(1);
    return high_water_mark_;
  }

  low_water_mark_ = high_water_mark_ = t;
  return t;
}

base::Time NavigationControllerImpl::TimeSmoother::GetSmoothedTime(
    base::Time t) {
  if (low_water_mark_ <= t && t <= high_water_mark_) {
    high_water_mark_ += base::TimeDelta::FromMicroseconds(1);
    return high_water_mark_;
  }

  low_water_mark_ = high_water_mark_ = t;
  return t;
}
