buildbot_test_toolchains:  make patch number a parameter.

We want to use the buildbot_test_toolchains.py to measure the
performance gap between gcc and clang. So we need a different
patch to create the image built with clang.

BUG=none
TEST=buildbot_test_toolchains.py now accepts --patch

Change-Id: I45dfd79630cea217bc6134802270c6e13b4121c1
Reviewed-on: https://chrome-internal-review.googlesource.com/227806
Reviewed-by: Caroline Tice <cmtice@google.com>
Commit-Queue: Yunlian Jiang <yunlian@google.com>
Tested-by: Yunlian Jiang <yunlian@google.com>
1 file changed