Add parameter to exclude PartitionAllocSupport from PartialLowEndMode.

Looking at the blink_perf.parser regression, it seems to be caused
by changing ThreadCache limits. PartitionAllocSupport changes the
limits by using ThreadCacheRegistry::SetThreadCacheMultiplier()
when PartialLowEndMode (and also LowEndMode) is enabled.

So add a parameter to PartialLowEndMode feature to exclude
PartitionAllocSupport when a process is not renderer and the param is
enabled, because the benchmark checks mainly renderer performance.
We will add a new group to the study and will see how the exclusion
affect performance and memory.

c.f. blink_perf.parser results comparing between disabled and
enabled with excluding PartitionAllocSupport are:
https://pinpoint-dot-chromeperf.appspot.com/job/1764fa53e60000
https://pinpoint-dot-chromeperf.appspot.com/job/12858f53e60000

Bug: 1434873, 1444131, 1453300
Change-Id: Id9ad475fa9cd0207d84a53c850d9189f591e6f33
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4679467
Reviewed-by: Bartek Nowierski <bartekn@chromium.org>
Commit-Queue: Takashi Sakamoto <tasak@google.com>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1170287}