Make PRESUBMIT.py choose appropriate trybots for pnacl checkins.
Make PRESUBMIT.py choose appropriate trybots for pnacl checkins.

Because apparently I am too lazy to use --bot= 4 times.

BUG=none
TEST=git try

Review URL: https://chromiumcodereview.appspot.com/10538030

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@8880 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

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