Don't update URL bar or SSL icon for pending history navs until they commit.

      BUG=89564
TEST=Go back or forward to a slow URL.  No omnibox change until it commits.


Review URL: http://codereview.chromium.org/7790018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@98853 0039d316-1c4b-4281-b951-d872f2087c98