[Sampling profiler] Encapsulate Mac stack walking 3/4: frame recording

The platform-native stack walking needs to be encapsulated into a function that
can be invoked in an alternating fashion with V8 unwinding, once supported. This
change inlines the frame recording into the core stack walking function. The
encapsulation requires inlining otherwise-sensible abstractions to enable
creation of future abstractions that can be used across platforms. No functional
change is intended.

Bug: 931418
Change-Id: I40880b76b65cda63892ce98395a0fcc46ec3259c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1513209
Commit-Queue: Mike Wittman <[email protected]>
Reviewed-by: Charlie Andrews <[email protected]>
Cr-Commit-Position: refs/heads/master@{#641326}
1 file changed