run_tests.py: find test executables in an in-Chromium build.
run_tests.py: find test executables in an in-Chromium build.

BUG=crashpad:12
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/996433002

chromium/crashpad,atom/crashpad,hankbao/Crashpad,hokein/crashpad,atom/crashpad,hankbao/Crashpad,Chilledheart/crashpad,Chilledheart/crashpad,chromium/crashpad,hankbao/Crashpad,Chilledheart/crashpad,hokein/crashpad,hokein/crashpad,chromium/crashpad,atom/crashpad