[scheduler] Add options to TaskQueue::InsertFence

[scheduler] Add options to TaskQueue::InsertFence

Make TaskQueue::InsertFence configurable and allow to insert a fence
in the beginning for the TaskQueue, effectively disabling it.
It will allow TaskQueueThrottler to use only fences without disabling
and enabling queues.

R=alexclarke@chromium.org,skyostil@chromium.org
BUG=638542
Review-Url: https://codereview.chromium.org/2533603002
Cr-Commit-Position: refs/heads/master@{#434542}
(cherry picked from commit d15597b8f924879440a66ef0f12f9a939b7c30ea)

Committed: https://chromium.googlesource.com/chromium/src/+/6abf248fbb96094a0ee7c103840eeccb23b38a31

[altimin, 2016-12-01 15:02:50]

Description was changed from

==========
[scheduler] Add options to TaskQueue::InsertFence

Make TaskQueue::InsertFence configurable and allow to insert a fence
in the beginning for the TaskQueue, effectively disabling it.
It will allow TaskQueueThrottler to use only fences without disabling
and enabling queues.

R=alexclarke@chromium.org,skyostil@chromium.org
BUG=638542

Review-Url: https://codereview.chromium.org/2533603002
Cr-Commit-Position: refs/heads/master@{#434542}
(cherry picked from commit d15597b8f924879440a66ef0f12f9a939b7c30ea)
==========

to

==========
[scheduler] Add options to TaskQueue::InsertFence

Make TaskQueue::InsertFence configurable and allow to insert a fence
in the beginning for the TaskQueue, effectively disabling it.
It will allow TaskQueueThrottler to use only fences without disabling
and enabling queues.

R=alexclarke@chromium.org,skyostil@chromium.org
BUG=638542

Review-Url: https://codereview.chromium.org/2533603002
Cr-Commit-Position: refs/heads/master@{#434542}
(cherry picked from commit d15597b8f924879440a66ef0f12f9a939b7c30ea)

Committed:
https://chromium.googlesource.com/chromium/src/+/6abf248fbb96094a0ee7c103840e...
==========

[altimin, 2016-12-01 15:02:51]

Committed patchset #1 (id:1) manually as
6abf248fbb96094a0ee7c103840eeccb23b38a31.

[alex clarke (OOO till 29th), 2016-12-01 15:07:11]

lgtm