Fixes the condition of Google logo for app_list voice search UI.

It is not necesarily chromeos only.

BUG=344158
TBR=oshima@chromium.org, xiyuan@chromium.org
TEST=none

Review URL: https://codereview.chromium.org/168623002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251594 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251594