Don't focus the location bar for NTP navigations in non-selected tabs.

BUG=677716
TEST=See bug for repro steps.

Review-Url: https://codereview.chromium.org/2624373002
Cr-Commit-Position: refs/heads/master@{#443338}
  void DontProceed() { interstitial_page_->DontProceed(); }

  void DontProceed() { interstitial_page_->DontProceed(); }
