The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f03480fa6ad6fc2874c145426b46ab655398064e

commit f03480fa6ad6fc2874c145426b46ab655398064e
Author: Alexander Timin <altimin@chromium.org>
Date: Wed Jun 27 12:50:40 2018

[scheduler] Prioritise N compositor tasks when processing input.

Support temporarily increased priority for compositor tasks for input:
- Explicit OnMainFrameRequestedForInput signal (new)
- Implicit presence of input tasks.

This patch does not change default behaviour, but add Finch hooks for enabling
these options and controlling the number of tasks N.

R=skyostil@chromium.org,alexclarke@chromium.org
BUG=853771

Change-Id: Id82b712e46108c51a948a66cfd31556e04eb457a
Reviewed-on: https://chromium-review.googlesource.com/1104677
Reviewed-by: Alex Clarke <alexclarke@chromium.org>
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Commit-Queue: Alexander Timin <altimin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570742}
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/content/renderer/input/main_thread_event_queue.cc
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/public/platform/scheduler/test/fake_renderer_scheduler.h
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/public/platform/scheduler/test/mock_renderer_scheduler.h
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/public/platform/scheduler/web_thread_scheduler.h
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/renderer/platform/scheduler/BUILD.gn
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/renderer/platform/scheduler/child/features.h
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/renderer/platform/scheduler/common/web_thread_scheduler.cc
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/renderer/platform/scheduler/main_thread/main_thread_scheduler_impl.cc
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/renderer/platform/scheduler/main_thread/main_thread_scheduler_impl.h
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/renderer/platform/scheduler/main_thread/main_thread_scheduler_impl_unittest.cc
[add] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/renderer/platform/scheduler/main_thread/prioritize_compositing_after_input_experiment.cc
[add] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/renderer/platform/scheduler/main_thread/prioritize_compositing_after_input_experiment.h
[modify] https://crrev.com/f03480fa6ad6fc2874c145426b46ab655398064e/third_party/blink/renderer/platform/scheduler/test/fake_renderer_scheduler.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e38ad59a34b356c0315e13da8829ba7ef78bfe6b

commit e38ad59a34b356c0315e13da8829ba7ef78bfe6b
Author: Alexander Timin <altimin@chromium.org>
Date: Tue Aug 21 19:42:39 2018

[scheduler] Enable prioritising compositing after input on waterfall

R=rkaplow@chromium.org
BUG=853771

Change-Id: I9f569103758c4f174b921925f1f0f2f2d7503553
Reviewed-on: https://chromium-review.googlesource.com/1183677
Reviewed-by: Robert Kaplow (slow) <rkaplow@chromium.org>
Commit-Queue: Alexander Timin <altimin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584885}
[modify] https://crrev.com/e38ad59a34b356c0315e13da8829ba7ef78bfe6b/testing/variations/fieldtrial_testing_config.json