Sort zones so that workers are on top.
Sort zones so that workers are on top.

If all zones are available when the TracksPanel initializes, make sure
the one with frames is on the bottom.

looker/tracing-framework,feisuo/tracing-framework,lollerbus/tracing-framework,lollerbus/tracing-framework,mcanthony/tracing-framework,vinodpanicker/tracing-framework,zhaoz/tracing-framework,vinodpanicker/tracing-framework,feisuo/tracing-framework,google/tracing-framework,looker/tracing-framework,google/tracing-framework,lollerbus/tracing-framework,looker/tracing-framework,zhaoz/tracing-framework,dockbiz/tracing-framework,dockbiz/tracing-framework,mcanthony/tracing-framework,mcanthony/tracing-framework,dockbiz/tracing-framework,looker/tracing-framework,lollerbus/tracing-framework,vinodpanicker/tracing-framework,feisuo/tracing-framework,zhaoz/tracing-framework,mcanthony/tracing-framework,dockbiz/tracing-framework,zhaoz/tracing-framework,feisuo/tracing-framework,google/tracing-framework,vinodpanicker/tracing-framework,google/tracing-framework