Fix download item icon.
Fix download item icon.

BUG=none
TEST=Download something, note that the correct item shows up in the shelf.

Review URL: http://codereview.chromium.org/150015

git-svn-id: http://src.chromium.org/svn/trunk/src@19640 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: dcd26234f77071f911abd8533df50613939b9e3c
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser