[Linux] Fix base_unittests for GCC 4.5.1
[Linux] Fix base_unittests for GCC 4.5.1

This is upstreaming a Gentoo Linux patch.

I have encountered this tiny compile issue
when using a more recent GCC.

TEST=none
BUG=none
Review URL: http://codereview.chromium.org/5791001

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@68933 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