wstring: use FilePath::value() on Windows to get wstrings
wstring: use FilePath::value() on Windows to get wstrings

BUG=69467

Review URL: http://codereview.chromium.org/6334030

git-svn-id: http://src.chromium.org/svn/trunk/src@73350 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 2fa1efcf6ec4add2c0453b108cf12d1ea109d285
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