Change URL back to the previous one if the typed URL causes file download.
Change URL back to the previous one if the typed URL causes file download.

This is the successor to http://codereview.chromium.org/115704

TESTED=manually

TEST=Type any URL that causes download, e.g.,
ftp://ftp.vim.org/pub/vim/pc/gvim72.zip into the omnibox.
Without this change the URL remains there. With this change,
the URL is changed back to the original one.

BUG=1904


Review URL: http://codereview.chromium.org/126266

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@18790 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