[MessageLoop] Only count tasks actually in the DelayedQueue as pending hi-res tasks.

This count only matters when reaching MessageLoop::DoIdleWork() at
which point the TriageQueue is empty by definition (and tasks in the
DeferredQueue do not matter). This CL is therefore a no-op behavior
wise.

In an upcoming change, the thread-safe |incoming_queue_| will move to
MessageLoopTaskRunner and dropping unecessary hi-res counts now will
make this transition simpler.

This also allows disconnecting DelayedQueue and DeferredQueue from their
outer class.

R=danakj@chromium.org, kylechar@chromium.org

Bug: 708584, 854237
Change-Id: Icf36f1e425a8320fb14a4c561c529a9ea2389e0f
Reviewed-on: https://chromium-review.googlesource.com/1103120
Commit-Queue: Gabriel Charette <gab@chromium.org>
Reviewed-by: kylechar <kylechar@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568586}
2 files changed