Add assets for experimental app list banner.

This is the binary potion of:
https://codereview.chromium.org/173423002/

BUG=344442
R=oshima@chromium.org
TBR=oshima@chromium.org

Review URL: https://codereview.chromium.org/180733002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253312 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253312