Adding support for --test argument
Adding support for --test argument

BUG=Cannot use this from Chrome buildbot scripts.
TEST=Ran tools/valgrind-webrtc/webrtc_tests.sh --test out/Debug/test_support_unittests

Review URL: https://webrtc-codereview.appspot.com/784006

git-svn-id: 917f5d3ca488f358c4d40eaec14422cf392ccec9@2737 4adac7df-926f-26a2-2b94-8c16560cd09d

mwgoldsmith/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,mwgoldsmith/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,mwgoldsmith/ilbc,TimothyGu/libilbc,TimothyGu/libilbc,mwgoldsmith/ilbc,mwgoldsmith/libilbc,TimothyGu/libilbc,mwgoldsmith/ilbc,ShiftMediaProject/libilbc,mwgoldsmith/ilbc,ShiftMediaProject/libilbc,mwgoldsmith/libilbc,ShiftMediaProject/libilbc