viz: Enable split occluded quads feature by default

crrev.com/c/2103721 added a flag to toggle the optimization.
The flag was disable by default so that it can be merged back
(hopefully without any conflict) to 81.

This patch reenables the feature on ToT by default.

Bug: 1061708
Test: viz_unittests without scopedfeature
Change-Id: Ibabc573a42c0750552982d02d3471798f59eb0f1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2103722
Commit-Queue: Daniele Castagna <dcastagna@chromium.org>
Reviewed-by: Gil Dekel <gildekel@chromium.org>
Reviewed-by: Sasha McIntosh <sashamcintosh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755894}

components/viz/common/features.cc

@@ -60,7 +60,7 @@ const base::Feature kUseRealBuffersForPageFlipTest{
 
 // Whether we should split partially occluded quads to reduce overdraw.
 const base::Feature kSplitPartiallyOccludedQuads{
-    "SplitPartiallyOccludedQuads", base::FEATURE_DISABLED_BY_DEFAULT};
+    "SplitPartiallyOccludedQuads", base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kUsePreferredIntervalForVideo{
     "UsePreferredIntervalForVideo", base::FEATURE_DISABLED_BY_DEFAULT};

components/viz/service/display/display_unittest.cc

@@ -11,10 +11,8 @@
 #include "base/test/bind_test_util.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "base/test/null_task_runner.h"
-#include "base/test/scoped_feature_list.h"
 #include "cc/base/math_util.h"
 #include "cc/test/scheduler_test_common.h"
-#include "components/viz/common/features.h"
 #include "components/viz/common/frame_sinks/begin_frame_source.h"
 #include "components/viz/common/frame_sinks/copy_output_request.h"
 #include "components/viz/common/frame_sinks/copy_output_result.h"
@@ -908,9 +906,6 @@ TEST_F(DisplayTest, CompositorFrameDamagesCorrectDisplay) {
 // split because splitting may affect how the filter applies to an
 // underlying quad.
 TEST_F(DisplayTest, DrawOcclusionWithIntersectingBackdropFilter) {
-  base::test::ScopedFeatureList feature_list;
-  feature_list.InitAndEnableFeature(features::kSplitPartiallyOccludedQuads);
-
   RendererSettings settings;
   settings.minimum_fragments_reduced = 0;
   SetUpGpuDisplay(settings);
@@ -3953,9 +3948,6 @@ TEST_F(DisplayTest, DrawOcclusionWithRoundedCornerDoesOcclude) {
 }
 
 TEST_F(DisplayTest, DrawOcclusionSplit) {
-  base::test::ScopedFeatureList feature_list;
-  feature_list.InitAndEnableFeature(features::kSplitPartiallyOccludedQuads);
-
   SetUpGpuDisplay(RendererSettings());
 
   StubDisplayClient client;
@@ -4051,9 +4043,6 @@ TEST_F(DisplayTest, DrawOcclusionSplit) {
 // complexity reduction in visible regions. For more details, see:
 // https://tinyurl.com/RegionComplexityReduction#heading=h.fg95k5w5t791
 TEST_F(DisplayTest, FirstPassVisibleComplexityReduction) {
-  base::test::ScopedFeatureList feature_list;
-  feature_list.InitAndEnableFeature(features::kSplitPartiallyOccludedQuads);
-
   SetUpGpuDisplay(RendererSettings());
 
   StubDisplayClient client;
@@ -4166,9 +4155,6 @@ TEST_F(DisplayTest, FirstPassVisibleComplexityReduction) {
 // since the number of saved fragments would only be 100x100 which is lower than
 // our threshold 128x128.
 TEST_F(DisplayTest, DrawOcclusionSplitDeviceScaleFactorFractional) {
-  base::test::ScopedFeatureList feature_list;
-  feature_list.InitAndEnableFeature(features::kSplitPartiallyOccludedQuads);
-
   SetUpGpuDisplay(RendererSettings());
 
   StubDisplayClient client;