Make Mac clang bot 32-bit
Make Mac clang bot 32-bit

All our other Mac bots are for 32-bit.  Make this one too.

BUG= none
TEST= none

R=bradnelson@google.com

Review URL: http://codereview.chromium.org/7977011

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@6741 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

nacl-webkit/native_client,sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,sbc100/native_client