Change the asset for the question mark icon in autofill.

BUG=319070
R=dbeam@chromium.org, oshima@chromium.org

Review URL: https://codereview.chromium.org/72453002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235233 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235233