Initialized file_util variable to NULL.
Initialized file_util variable to NULL.

This supresses the -Wmaybe-uninitialized warning when compiling with gcc-4.6.0.

BUG=none
TEST=trybot.


Review URL: http://codereview.chromium.org/9104024

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@119963 0039d316-1c4b-4281-b951-d872f2087c98

yitian134/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,gavinp/chromium,yitian134/chromium,adobe/chromium,yitian134/chromium,gavinp/chromium,gavinp/chromium,gavinp/chromium,gavinp/chromium,ropik/chromium,ropik/chromium,adobe/chromium,gavinp/chromium,adobe/chromium,gavinp/chromium,yitian134/chromium,ropik/chromium,yitian134/chromium,ropik/chromium,adobe/chromium,adobe/chromium,yitian134/chromium,gavinp/chromium,adobe/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,adobe/chromium,gavinp/chromium,yitian134/chromium,ropik/chromium,gavinp/chromium,adobe/chromium,yitian134/chromium,ropik/chromium,ropik/chromium,adobe/chromium