Clean up remaining unused globals (on mac).

Found by clang's new -Wunused-const-variable.

BUG=290204
R=akalin@chromium.org, jamesr@chromium.org, koz@chromium.org, piman@chromium.org, sergeyu@chromium.org, thestig@chromium.org, vitalybuka@chromium.org
TBR=cpu, dmichael, joi, xhwang

Review URL: https://codereview.chromium.org/24579003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225281 0039d316-1c4b-4281-b951-d872f2087c98