Fix ChromeOS crash when device_path is NULL. TEST=None BUG=1698 Review URL: http://codereview.chromium.org/661230
Fix ChromeOS crash when device_path is NULL.
TEST=None
BUG=1698
Review URL: http://codereview.chromium.org/661230

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@40188 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