The timeline summary should include refresh rate information.
The things to include should be:

• The percentage of the frames running on 30hz.
• The percentage of the frames running on 60hz.
• The percentage of the frames running on 90hz.
• The percentage of the frames running on 80hz.
• The percentage of the frames running on 120hz.
• The number of the frames running on an illegal refresh rate.

Since there would be rounding errors calculating refresh rates. We should consider add an error margin when determine refresh rate.
5Hz could be a value we try. (e.g. we consider a frame with 35hz as a valid 30hz frame)