Use WorkspaceLayoutManager for AlwaysOnTop and Lock containers

BUG=338906
TEST=Tested on the device and confirmed that login/lock screens are fine.

Review URL: https://codereview.chromium.org/148173014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247733 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 247733
Adds the hotword off icon for app-list.

BUG=313904
R=xiyuan@chromium.org
TBR=oshima@chromium.org
TEST=none

Review URL: https://codereview.chromium.org/145353016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247734 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 247734