Windows: improve menu item initialization.

This patch prevents the 'Restore' option to be shown when the window can
not be resized and the 'Minimize' option is no longer disabled if the
window can not be maximized.

BUG=None

Review URL: https://codereview.chromium.org/137793003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245849 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245849