Fix compile with gcc-4.4

This is the only change that needs to be made to Chrome
(except for Blink changes, also small) to compile with gcc-4.4.

One example of a distro that still uses it is RHEL 6.

BUG=none
R=erikwright@chromium.org

Review URL: https://codereview.chromium.org/69813017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235821 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235821