only flake is on fuchsia_x64

[ RUN      ] ServiceWorkerHandleTest.DispatchExtendableMessageEvent_FromClient
[160077:626950491:0309/223947.373589:269794585:ERROR:base_paths_fuchsia.cc(37)] Not implemented reached in bool base::PathProviderFuchsia(int, base::FilePath *)
[160077:755400943:0309/223947.614121:270035155:FATAL:url_request_job_factory.cc(19)] Check failed: (thread_checker_).CalledOnValidThread().

Related to  Issue 820620 ?

ServiceWorkerHandleTest.DispatchExtendableMessageEvent_FromClient crashed with:

[00270.285] 04060.04110> [ RUN      ] ServiceWorkerHandleTest.DispatchExtendableMessageEvent_FromClient
[00270.285] 04060.04110> [160077:626950491:0309/223947.373589:269794585:ERROR:base_paths_fuchsia.cc(37)] Not implemented reached in bool base::PathProviderFuchsia(int, base::FilePath *)
[00270.285] 04060.04110> [160077:755400943:0309/223947.614121:270035155:FATAL:url_request_job_factory.cc(19)] Check failed: (thread_checker_).CalledOnValidThread().
#00: base::debug::StackTrace::StackTrace(unsigned long) at base/debug/stack_trace_fuchsia.cc:174
#01: endl<char, std::__1::char_traits<char> > at buildtools/third_party/libc++/trunk/include/ostream:1001
      (inlined by) operator<< at buildtools/third_party/libc++/trunk/include/ostream:195
      (inlined by) ~LogMessage at base/logging.cc:595
#02: ~URLRequestJobFactory at net/url_request/url_request_job_factory.cc:20
#03: ~URLRequestJobFactoryImpl at net/url_request/url_request_job_factory_impl.cc:23
#04: reset at buildtools/third_party/libc++/trunk/include/memory:2596
      (inlined by) ~unique_ptr at buildtools/third_party/libc++/trunk/include/memory:2553
      (inlined by) ~URLRequestContextStorage at net/url_request/url_request_context_storage.cc:40
#05: reset at buildtools/third_party/libc++/trunk/include/memory:2596
      (inlined by) ~unique_ptr at buildtools/third_party/libc++/trunk/include/memory:2553
      (inlined by) ~TestURLRequestContext at net/url_request/url_request_test_util.cc:66
#06: ~TestContextURLRequestContextGetter at content/public/test/test_browser_context.cc:39
      (inlined by) ~TestContextURLRequestContextGetter at content/public/test/test_browser_context.cc:39
#07: OnDestruct at net/url_request/url_request_context_getter.cc:37
#08: DoDelete at base/sequenced_task_runner_helpers.h:24
#09: Run at base/callback.h:95
      (inlined by) RunTask at base/debug/task_annotator.cc:61
#10: ~ScopedTracer at base/trace_event/trace_event.h:1106
      (inlined by) RunOrSkipTask at base/task_scheduler/task_tracker.cc:461
#11: RunOrSkipTask at base/task_scheduler/task_tracker_posix.cc:25
#12: RunOrSkipTask at base/test/scoped_task_environment.cc:286
#13: RunAndPopNextTask at base/task_scheduler/task_tracker.cc:353
#14: swap<base::internal::Sequence *> at buildtools/third_party/libc++/trunk/include/type_traits:4646
      (inlined by) swap at base/memory/scoped_refptr.h:231
      (inlined by) operator= at base/memory/scoped_refptr.h:227
      (inlined by) ThreadMain at base/task_scheduler/scheduler_worker.cc:85
#15: ThreadFunc at base/threading/platform_thread_posix.cc:78
#16: pc 0x76699e20bde6 (libc.so,0x10de6)
#17: pc 0x76699e281549 (libc.so,0x86549)
[00270.292] 04060.04110>
[00270.292] 04060.04110> [2205/5377] ServiceWorkerHandleTest.DispatchExtendableMessageEvent_FromClient (CRASHED)

The explicit crash stack provided at c#5 (Thanks wez@ !) is different with  issue 820620 , but I suspect probably this may also be caused by the same root cause.

I prepared a fix CL https://chromium-review.googlesource.com/c/chromium/src/+/958126 for  issue 820620 , which will re-enable this _FromClient test, I think we can land it and then observe whether this flake will appear again, if not then we are all happy, if flake appears again then we need more investigation..

Just a update:
The flaky test ServiceWorkerHandleTest.DispatchExtendableMessageEvent_FromClient has already been re-enabled yesterday by the CL mentioned at c#7, and we can see that no new flakes are detected until now (24 hours passed).
Suppose this has been fixed.

Thanks Leon, marking fixed. As far as I can tell, this is just a crash in the test code fixed by https://chromium-review.googlesource.com/c/chromium/src/+/958126 and we don't need merges anywhere.