Fixes crash in dragging from download manager on chrome os.
Fixes crash in dragging from download manager on chrome os.

BUG=36516
TEST=on chromeos drag from the download manager and make sure we don't
     crash.

Review URL: http://codereview.chromium.org/660088

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@40040 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