GitLab

This patch makes the renderer's compositor use blink runtime feature
flags to initialize the layer list setting. With this change we no
longer need to separately plumb both a blink feature (i.e., BGPT or
SPV2) and a layer list setting. This prevents the confusion situation of
having the blink feature flags not match the compositor's layer list
setting. This also simplifies the release of Blink Generated Property
Trees because we can use the existing processes for transitioning a
blink feature from test to experimental to stable.

The primary code change is to remove the --enable-layer-lists flag and
instead have render_widget.cc initialize the use_layer_lists setting
from blink feature flags. This patch also cleans up some plumbing for
the --enable-slimming-paint-v2 flag and adds TODOs to remove both
--enable-slimming-paint-v2 and --enable-blink-gen-property-trees.

Bug: 836884
Cq-Include-Trybots: luci.chromium.try:linux-blink-gen-property-trees;luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Iffdefc896abb00e6692a0d77b4fde5f628cb8ff5
Reviewed-on: https://chromium-review.googlesource.com/c/1278988Reviewed-by: enne <enne@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600486}