Spinner image replaced on gaia and eula screens.

BUG=284538
NOTRY=true

Review URL: https://codereview.chromium.org/25066002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225711 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225711