Revert 239419 "Enable the task manager to be put into immersive ..." because the CL was committed with an incorrect description

TBR=pkotwicz@chromium.org

Review URL: https://codereview.chromium.org/109683003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239420 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239420