Do not use NavigationEntry to block history navigations.

This is no longer necessary after r477371.

BUG=777419
TEST=See bug for repro steps.

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_site_isolation
Change-Id: I701e4d4853858281b43e3743b12274dbeadfbf18
Reviewed-on: https://chromium-review.googlesource.com/733959
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Commit-Queue: Charlie Reis <creis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#511942}
void NavigationControllerImpl::NotifyEntryChanged(
    const NavigationEntry* entry) {
  EntryChangedDetails det;
  det.changed_entry = entry;
  det.index = GetIndexOfEntry(
      NavigationEntryImpl::FromNavigationEntry(entry));
  delegate_->NotifyNavigationEntryChanged(det);
}

void NavigationControllerImpl::NotifyEntryChanged(
    const NavigationEntry* entry) {
  EntryChangedDetails det;
  det.changed_entry = entry;
  det.index = GetIndexOfEntry(
      NavigationEntryImpl::FromNavigationEntry(entry));
  delegate_->NotifyNavigationEntryChanged(det);
}
