Revert of Move stack trace extraction code out of TickSample::Init (patchset #1 id:1 of https://codereview.chromium.org/2007343003/ )

Reason for revert:
Make MSAN arm bot flaky

Original issue's description:
> Move stack trace extraction code out of TickSample::Init
>
> Make it a part of V8 API GetStackSample function.
> Also expose external_callback_entry in SampleInfo to break dependency
> of clients on internal V8 structures.
>
> BUG=v8:4789
>
> Committed: https://crrev.com/70acfe39c07322144f5fe9b40bb584a8b1099ffd
> Cr-Commit-Position: refs/heads/master@{#36831}

TBR=yangguo@chromium.org,lpy@chromium.org,jochen@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4789

Review-Url: https://codereview.chromium.org/2049903002
Cr-Commit-Position: refs/heads/master@{#36835}