Add ASYNC_STEP support to trace_event and change START to ASYNC_BEGIN.

BUG=116095


Review URL: http://codereview.chromium.org/9522010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@124348 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: 7c52775c8c3696aad8a9bf92f94dbc87add202c1
5 files changed
tree: e6ec25f47676627d185457d09fc58986bd1db601
  1. base/
  2. build/
  3. dbus/
  4. ipc/
  5. testing/
  6. third_party/