Make streamlined hosted apps only able to toggle between opening as tab and window.

This CL removes the ability for streamlined hosted apps to choose to launch as
pinned tabs or fullscreen. The NTP4 and app launcher context menus now provide
only the "Open as window" option which toggles on and off to indicate launching
as a window and tab respectively.

BUG=

Review URL: https://codereview.chromium.org/26440005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230323 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230323