Use current dir as working directory if %TEMP% directory doesnt work.
Use current dir as working directory if %TEMP% directory doesnt work.

BUG=6471
TEST=set TMP to invalid dir and run mini_installer.exe, it should still work.

Review URL: http://codereview.chromium.org/125068

git-svn-id: http://src.chromium.org/svn/trunk/src@18391 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: b787d407c4d73e39fc6a3dd5d0b18b4b405fcdb9
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