The charts tend to be static for many days in a row, which will now be
filtered to be more succinct.
Also fixes issue parsing when a message interrupts the formatted *RESULT
token.

Bug: angleproject:3435
Change-Id: I9ed213844de469c7a8240ee95aab82451888edf1
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1606029Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Jonah Ryan-Davis <jonahr@google.com>