There haven't been automated tests for this since we're calling an OS API and expecting it to return data within certain constraints. All we could really do is add a test that synthesizes forms that that data might take and hope that the OS API doesn't start returning something else.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a9abedb1e941cc2512f65bb3f66d5446033682d3

commit a9abedb1e941cc2512f65bb3f66d5446033682d3
Author: wez <wez@chromium.org>
Date: Sun Feb 05 02:21:23 2017

Add unit-test for SharedSampler handling of zero-thread processes.

BUG= 683849 ,  673175 

Review-Url: https://codereview.chromium.org/2657393003
Cr-Commit-Position: refs/heads/master@{#448166}

[modify] https://crrev.com/a9abedb1e941cc2512f65bb3f66d5446033682d3/chrome/browser/BUILD.gn
[modify] https://crrev.com/a9abedb1e941cc2512f65bb3f66d5446033682d3/chrome/browser/task_manager/sampling/shared_sampler.h
[modify] https://crrev.com/a9abedb1e941cc2512f65bb3f66d5446033682d3/chrome/browser/task_manager/sampling/shared_sampler_win.cc
[add] https://crrev.com/a9abedb1e941cc2512f65bb3f66d5446033682d3/chrome/browser/task_manager/sampling/shared_sampler_win_defines.h
[rename] https://crrev.com/a9abedb1e941cc2512f65bb3f66d5446033682d3/chrome/browser/task_manager/sampling/shared_sampler_win_unittest.cc
[modify] https://crrev.com/a9abedb1e941cc2512f65bb3f66d5446033682d3/chrome/test/BUILD.gn