GitLab

These functions where invaluable when trying to debug and fix the
cc::OrderedTestRunner as they let me easily inspect the tasks without having to
fire up GDB. They should also be useful in development / testing of other task
runners.

Added a very simple test for ShouldRunBefore which shows this stuff working. If
that test fails, the output looks like the following;
-------------------------------------------------------------------------------
../../base/test/test_pending_task_unittest.cc:49: Failure
Value of: task_after.ShouldRunBefore(task_first)
  Actual: false
Expected: true
TestPendingTask(
  {"delay":2000,"nestability":"NESTABLE","post_time":0,
   "posting_function":"Unknown@Unknown:-1","run_at":2000}
).ShouldRunBefore(TestPendingTask(
  {"delay":1000,"nestability":"NESTABLE","post_time":0,
   "posting_function":"Unknown@Unknown:-1","run_at":1000})
)
-------------------------------------------------------------------------------

BUG=380889

Review URL: https://codereview.chromium.org/491743002

Cr-Commit-Position: refs/heads/master@{#292370}