Ensure that we don't attempt to switch to desktop mode from Chrome ASH on Windows for external http/https url navigations from
Chrome.

The current behavior is that there is a flash due to a switch to desktop and then back to metro for external http/https url
navigations.

BUG=328308
R=sky@chromium.org

Review URL: https://codereview.chromium.org/106953004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241991 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241991