Do not change IME label in tray before hiding it.

BUG=343650
TEST=manually

Review URL: https://codereview.chromium.org/159903007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251337 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251337