Revert 175810 - looks like this revert broke some tests.

Revert 175810 - looks like this revert broke some tests.
> Revert 175782
> > InspectorTimeline improvements
> > 
> > - Split out inspector-neutral parts of InspectorTimeline in preparation for
> >   about:tracing-based timeline
> > - Use event.name instead of type, which is in keeping with trace-viewer
> > - Use ms on units since the rest of telemetry uses seconds, but
> >   for precision reasons, ms makes sense to stick with
> > - Move arguments to event.args so that params get consistent treatment
> >   e.g. event.foo['bar'] is less consistent than event.args['foo']['bar']
> > - Improved test coverage of model, events, parsing
> > - event.self_time which represents
> > - drop events lacking start- or end- times
> > 
> > R=bulach@chromium.org
> > NOTRY=True
> > 
> > Review URL: https://chromiumcodereview.appspot.com/11818024
> 
> TBR=nduca@chromium.org
> Review URL: https://codereview.chromium.org/11733008

TBR=sullivan@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=175825