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Records work ids along with samples to distinguish which samples came
from which work items (i.e. tasks, user interface event handlers, etc.)
This information will be used to infer coarse work item durations and
from that information, jankiness.

Task id recording takes place while the thread is suspended so must
be implemented in a lockless fashion.

The corresponding Mac implementation will be much more involved so is
deferred to a future CL.

This is a reland of 721cd487.

Change-Id: Ife21309d469ab7ffae3cd41ea069cfafb3747dd7
Reviewed-on: https://chromium-review.googlesource.com/c/1417835
Commit-Queue: Mike Wittman <wittman@chromium.org>
Reviewed-by: François Doray <fdoray@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625755}