Update tracing framework to optionally use a ringbuffer.
This updates the code to allow passing a continuous_tracing option into the trace framework. When enabled a ringbuffer will be used for event storage instead of a simple vector.
The continuous_tracing option will allow us to trace for longer periods of time without needing to worry that we'll stop tracing before hitting the event we're looking for.
BUG=156025
Review URL: https://chromiumcodereview.appspot.com/12096115
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@188505 0039d316-1c4b-4281-b951-d872f2087c98
4 files changed
