Rather than specifically update the DOM of the Statistics and Sources sections whenever adding/removing a filter, we could create a new `WI.CPUTimelineStatisticsView` that has it's own `layout()` which we can then call `needsLayout` on so only it will re`layout` when adding/removing filters. This would help reduce the overall size of CPUTimelineView.js and perhaps make some of the logic a bit more "chunk"able.