POSIX: Handle race conditions in file_util::CreateDirectory where multiple processes tries to create the same file system tree simultaneously.
POSIX: Handle race conditions in file_util::CreateDirectory where multiple processes tries to create the same file system tree simultaneously.

BUG=38112
TEST=none
Review URL: http://codereview.chromium.org/990002

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@41881 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