Don't delete the current NavigationEntry when leaving an interstitial page.

BUG=107182
TEST=See bug

Review URL: http://codereview.chromium.org/8976014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@115189 0039d316-1c4b-4281-b951-d872f2087c98
  void AddURLResult(const GURL& url,
                    SafeBrowsingService::UrlCheckResult checkresult) {
    FakeSafeBrowsingService* service =
        static_cast<FakeSafeBrowsingService*>(
            g_browser_process->safe_browsing_service());

    ASSERT_TRUE(service);
    service->AddURLResult(url, checkresult);
  }

  void AddURLResult(const GURL& url,
                    SafeBrowsingService::UrlCheckResult checkresult) {
    FakeSafeBrowsingService* service =
        static_cast<FakeSafeBrowsingService*>(
            g_browser_process->safe_browsing_service());

    ASSERT_TRUE(service);
    service->AddURLResult(url, checkresult);
  }
