All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=887252

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=45224cbe2a80636fd855343b92ddd6c4fa539b98405176c5121575ffae274298


Bot(s) for this bug's original alert(s):

Android Nexus5X WebView Perf

system_health.memory_mobile - Benchmark documentation link:
  https://bit.ly/system-health-benchmarks

memory.top_10_mobile - Benchmark documentation link:
  None

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/15fa4e0f640000

📍 Found a significant difference after 1 commit.
https://pinpoint-dot-chromeperf.appspot.com/job/15fa4e0f640000

[ptr-compr] Introduce BoundedPageAllocator and use it instead of CodeRange. by ishell@chromium.org
https://chromium.googlesource.com/v8/v8/+/37d87f610fd7ee27b68490cfe2d9c6061eeb100d
6.75e+06 → 6.863e+06 (+1.128e+05)

Understanding performance regressions:
  http://g.co/ChromePerformanceRegressions

Benchmark documentation link:
  None

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/8034b9a539a5d1947063f5ea9df1e0175dcacaaa

commit 8034b9a539a5d1947063f5ea9df1e0175dcacaaa
Author: Igor Sheludko <ishell@chromium.org>
Date: Fri Sep 28 11:01:50 2018

[heap] Add missing notification about freed code range

It was accidentally removed in CL that introduced BoundedPageAllocator.

This CL also cleans up the CodeRangeAddressHint a bit.

Bug:  v8:8096 , chromium:887252
Change-Id: Idc84796dd1ff1b440cbe3515732984264defcf2d
Reviewed-on: https://chromium-review.googlesource.com/1249125
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56287}
[modify] https://crrev.com/8034b9a539a5d1947063f5ea9df1e0175dcacaaa/src/heap/spaces.cc
[modify] https://crrev.com/8034b9a539a5d1947063f5ea9df1e0175dcacaaa/src/heap/spaces.h
[modify] https://crrev.com/8034b9a539a5d1947063f5ea9df1e0175dcacaaa/test/unittests/heap/spaces-unittest.cc