GTK: Preview images in file chooser.
GTK: Preview images in file chooser.

BUG=http://crbug.com/15500
TEST=select an image in a file chooser

Review URL: http://codereview.chromium.org/151100

git-svn-id: http://src.chromium.org/svn/trunk/src@19874 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 68cf8e60da6e2dcbde5d53dc935de111ab85ee21
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