fix intsafe.h compile errors on express/automatic toolchain on windows

R=nick@chromium.org, robliao@chromium.org
TBR=nick@chromium.org, robliao@chromium.org
BUG=308740

Review URL: https://codereview.chromium.org/29273003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229443 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229443