Avoid random stacktraces being printed from tools/test.py during test runs

Avoid random stacktraces being printed from tools/test.py during test runs

Previously the testing script was just printing interleaved stack traces with
all the other output. Which means it's not associatable with a single test and
is highly confusing!

This CL associates the stack trace information of tests which time out to the
particular test which timed out.

R=whesse@google.com

Committed: https://github.com/dart-lang/sdk/commit/b1c04f0538f68f9a9a59953e80adae4d015c58cd

[kustermann, 2016-11-22 15:11:38]

kustermann@google.com changed reviewers:
+ whesse@google.com

[Bill Hesse, 2016-11-22 15:18:04]

LGTM.  Much better.

[kustermann, 2016-11-23 07:39:33]

Description was changed from

==========
Avoid random stacktraces being printed from tools/test.py during test runs

Previously the testing script was just printing interleaved stack traces with
all the other output. Which means it's not associatable with a single test and
is highly confusing!

This CL associates the stack trace information of tests which time out to the
particular test which timed out.
==========

to

==========
Avoid random stacktraces being printed from tools/test.py during test runs

Previously the testing script was just printing interleaved stack traces with
all the other output. Which means it's not associatable with a single test and
is highly confusing!

This CL associates the stack trace information of tests which time out to the
particular test which timed out.

R=whesse@google.com

Committed:
https://github.com/dart-lang/sdk/commit/b1c04f0538f68f9a9a59953e80adae4d015c58cd
==========

[kustermann, 2016-11-23 07:39:34]

Committed patchset #1 (id:1) manually as
b1c04f0538f68f9a9a59953e80adae4d015c58cd (presubmit successful).