The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f63c4489e214ba01696e1c91b88fb50265936943

commit f63c4489e214ba01696e1c91b88fb50265936943
Author: Eric Seckler <eseckler@chromium.org>
Date: Mon Dec 04 10:46:58 2017

cc: Resume requested pipeline stages after deferred commits.

When commits are deferred during BeginMainFrame, ProxyMain looses the
state of max_requested_pipeline_stage_. As a result, the BMF/commit
after deferring may be aborted b/c it seemingly didn't have updates,
even though it did.

This patch ensures that ProxyMain resumes up to the previously
requested pipeline stage after un-deferring commits.

Bug:  791012 
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
Change-Id: Ib65c8f0adff15f49b7c5e372492ee5da55cf17c4
Reviewed-on: https://chromium-review.googlesource.com/803515
Commit-Queue: Eric Seckler <eseckler@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521307}
[modify] https://crrev.com/f63c4489e214ba01696e1c91b88fb50265936943/cc/trees/layer_tree_host_unittest.cc
[modify] https://crrev.com/f63c4489e214ba01696e1c91b88fb50265936943/cc/trees/proxy_main.cc