Chrome Version: ToT
OS: Linux

What steps will reproduce the problem?
(1) content_unittests --trace-to-file

What is the expected result?
Write default traces to trace.json

What happens instead?
[12426:12426:0123/152626.315918:605127914513:FATAL:thread_task_runner_handle.cc(29)] Check failed: current. Error: This caller requires a single-threaded context (i.e. the current task needs to run from a SingleThreadTaskRunner).
#0 0x7f4c535783ec base::debug::StackTrace::StackTrace()
#1 0x7f4c535a2dbc logging::LogMessage::~LogMessage()
#2 0x7f4c5362eba1 base::ThreadTaskRunnerHandle::Get()
#3 0x7f4c535e7c42 base::RunLoop::RunLoop()
#4 0x000001a89760 base::test::TraceToFile::EndTracingIfNeeded()
#5 0x000001a8968e base::test::TraceToFile::~TraceToFile()
#6 0x000001a81d42 base::TestSuite::~TestSuite()
#7 0x000001a44dde content::ContentTestSuiteBase::~ContentTestSuiteBase()
#8 0x0000015f90e8 main
#9 0x7f4c4a0b4f45 __libc_start_main
#10 0x00000061202a _start