Add a UI test for downloading in incognito mode.
Add a UI test for downloading in incognito mode.

This test opens an incognito window and verifies that
downloads work and that closing the incognito window
does not crash (see bug http://crbug.com/13983).

TEST=Test should run and not crash.
BUG=none

Review URL: http://codereview.chromium.org/126181

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@18534 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser