Bug 1981564 [wpt PR 54174] - Crash: Add initialize() method to CrashReportStorage, a=testonly

Automatic update from web-platform-tests
Crash: Add initialize() method to CrashReportStorage

This CL introduces the `initialize()` method to the `CrashReportStorage`
interface, introduced in [1] and [2]. This API gives an asynchronous gap
for the implementation to initialize any relevant backing memory for the
crash report storage.

In the current Chromium implementation, this isn't used since the web
APIs `set()` and `remove()` are backed by synchronous IPCs, but this
method is required by the spec proposal to allow for more sophisticated
mechanisms to be used for the backing memory. In Chromium, we are
exploring taking advantage of this in https://crrev.com/c/6788146, where
we're considering replacing `RenderFrameHostImpl::crash_storage_map_`
with a shared memory region that spans the browser and renderer process.

[1]:
https://github.com/WICG/crash-reporting/blob/gh-pages/crashReport-explainer.md
[2]: WICG/crash-reporting#37

R=creis, dcheng

Bug: 400432195
Change-Id: I7ee67d29c6d4601b4d7ecb2d0b54dd24d0111e39
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6819100
Reviewed-by: Steven Holte <holtechromium.org>
Commit-Queue: Dominic Farolino <domchromium.org>
Reviewed-by: Daniel Cheng <dchengchromium.org>
Reviewed-by: mmenke <mmenkechromium.org>
Reviewed-by: Charlie Reis <creischromium.org>
Cr-Commit-Position: refs/heads/main{#1497721}

--

wpt-commits: 50a4d0664f7b473db8998b06fed35769bda66774
wpt-pr: 54174

UltraBlame original commit: a8c0b56d143c68a5551c0f14ad2e8f0330639510

Author: marco-c