Revert 175782

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
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=175810