unified-heap: Avoid stand-alone Blink idle GCs

V8 has a mechanism for idle GCs that also triggers Blink collection with
unified heap. There is no reason to schedule stand-alone Blink idle GCs
based on fixed memory heuristics.

Depending on workload this reduces GC pressure of ~10-25% on Blink which amounts
to ~5-15% with unified heap. Local testing shows no significant regression in

Bug: 843903
Change-Id: I49ca889ae92ca3b45181fa9fe5468b9ffab5f67e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1528671
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641826}
1 file changed