In app windows, fallback to the product icon if there's no site favicon.
In app windows, fallback to the product icon if there's no site favicon.

TEST=Open the web inspector.  When it finishes loading, it should show
  the chromium icon instead of the last frame of the throbber.

Review URL: http://codereview.chromium.org/164159


git-svn-id: http://src.chromium.org/svn/trunk/src@22747 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 61cba255fb890930a293f72b3ddee270a5666a9d
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