Disallow posting tasks to SequencedWorkerPools by default.
We have observed crash reports in which SequencedWorkerPool workers
were active while redirection to TaskScheduler was enabled. This can
happen if a task is posted to a SequencedWorkerPool before redirection
to TaskScheduler is enabled. With this CL, DumpWithoutCrashing is
called if a task is posted to a SequencedWorkerPool too early. This
will help us find offending call sites.
BUG=622400
Review-Url: https://codereview.chromium.org/2445763002
Cr-Commit-Position: refs/heads/master@{#432913}
11 files changed
