Adds properties that configure filtering what patches trigger compile/test

Two new keys:
gtest_tests_filter_exclusions: If any of the patchs in the patch match
any of these regexs then we don't check dependencies and trigger a
compile.

filter_builders: list of builders that will run this code.

BUG=383609
TEST=none
R=darin@chromium.org

Review URL: https://codereview.chromium.org/340783006

git-svn-id: http://src.chromium.org/chrome/trunk/src/testing@279318 4ff67af0-8c30-449e-8e8b-ad334ec8d88c