Rewrite map pointer values to raw_ptr

This cl rewrites CTN<key, T*> into CTN<key, raw_ptr<T, CtnExperimental>>
where CTN is one of: std::map, std::unordered_map, base::flat_map

The following benchmarks were launched to ensure the cl does not
introduce any performance regression:
https://pinpoint-dot-chromeperf.appspot.com/job/10ce4602210000
https://pinpoint-dot-chromeperf.appspot.com/job/11e2fc0c210000
https://pinpoint-dot-chromeperf.appspot.com/job/16ca4ca8210000
https://pinpoint-dot-chromeperf.appspot.com/job/168ae33c210000

The identified bottlenecks were excluded from the rewrite. These are the
initial values before exclusions on motionmark_ramp_composite (for
example): https://pinpoint-dot-chromeperf.appspot.com/job/16987bf4210000

After Exclusions:
https://pinpoint-dot-chromeperf.appspot.com/job/168ae33c210000

AX-Relnotes: n/a.
Change-Id: I35c52d7427140361410db74e25e0cb8f7bd516db
Bug: 329428315
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5867189
Reviewed-by: danakj <danakj@chromium.org>
Owners-Override: danakj <danakj@chromium.org>
Commit-Queue: Ali Hijazi <ahijazi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1361899}
NOKEYCHECK=True
GitOrigin-RevId: 60a72b0afdb415164c8f72cb0cada4317e4464a1
2 files changed