Fixing issue of default launch mode when registry key is not present.
Removed launch mode decision based on touch screen capability.

BUG=314818
R=ananta@chromium.org, ananta, cpu
TESTS=Please see bug description for steps.

Review URL: https://codereview.chromium.org/50883005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232828 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232828