Add .clean_trace() to the APIs to delete the stale traces.

It'll become soon more complex for strace so it's preferable to have a proper
interface.

R=mad@chromium.org
BUG=98636
TEST=

Review URL: https://chromiumcodereview.appspot.com/10381112

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@136655 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed