This is a reland of commit ae4ee87601
Our Dart tests that check for symbolic stack traces assume the frame
number comes at the very start of the line. Thus, be lenient about
how many spaces we see before non-symbolic stack traces, but only
generate a prefix for the resulting symbolic stack traces if the
original stack trace had any initial non-whitespace content.
Original change's description:
> [native_stack_traces] Remove initial spaces check in stack trace lines.
>
> The strictness of the old "check for four spaces" was causing failures
> in `flutter symbolize`, and there's no reason to check how much initial
> whitespace we got prior to the line contents anyway.
>
> TEST=pkg/native_stack_traces/test/convert/regress_262474517_test
>
> Change-Id: I6a6e31732cb2a5b5d40a088b9a04877052726be2
> Bug: b/262474517
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/276905
> Reviewed-by: Daco Harkes <dacoharkes@google.com>
> Commit-Queue: Tess Strickland <sstrickl@google.com>
Bug: b/262474517
Change-Id: I3b0753404e00d535cf438e79078736f5d9a10dbc
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/277001
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
73c639a4ba