Plumb the feature flag for CompositingOptimizations to Blink.

Bug: 1115577

Change-Id: I17411a1e73aeccf9a242ee104ba2a7b963d08472
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2357093
Commit-Queue: Chris Harrelson <chrishtr@chromium.org>
Reviewed-by: Stefan Zager <szager@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799525}

content/child/runtime_features.cc

@@ -341,7 +341,8 @@ void SetRuntimeFeaturesFromChromiumFeatures() {
     {wf::EnableMediaFeeds, media::kMediaFeeds, kUseFeatureState},
     {wf::EnableRestrictGamepadAccess, features::kRestrictGamepadAccess,
      kEnableOnly},
-
+    {wf::EnableCompositingOptimizations,
+     blink::features::kCompositingOptimizations, kUseFeatureState},
   };
   for (const auto& mapping : blinkFeatureToBaseFeatureMapping) {
     SetRuntimeFeatureFromChromiumFeature(

third_party/blink/public/platform/web_runtime_features.h

@@ -251,6 +251,8 @@ class WebRuntimeFeatures {
   BLINK_PLATFORM_EXPORT static void EnableContentIndex(bool);
   BLINK_PLATFORM_EXPORT static void EnableRestrictGamepadAccess(bool);
 
+  BLINK_PLATFORM_EXPORT static void EnableCompositingOptimizations(bool);
+
  private:
   WebRuntimeFeatures();
 };

third_party/blink/renderer/modules/accessibility/ax_layout_object.cc

@@ -1450,9 +1450,16 @@ AXObject* AXLayoutObject::AccessibilityHitTest(const IntPoint& point) const {
       !layout_object_->IsBox())
     return nullptr;
 
-  // Must be called with lifecycle >= compositing clean.
-  DCHECK_GE(GetDocument()->Lifecycle().GetState(),
-            DocumentLifecycle::kCompositingAssignmentsClean);
+    // Must be called with lifecycle >= compositing clean
+#if DCHECK_IS_ON()
+  if (RuntimeEnabledFeatures::CompositingOptimizationsEnabled()) {
+    DCHECK_GE(GetDocument()->Lifecycle().GetState(),
+              DocumentLifecycle::kPrePaintClean);
+  } else {
+    DCHECK_GE(GetDocument()->Lifecycle().GetState(),
+              DocumentLifecycle::kCompositingAssignmentsClean);
+  }
+#endif
 
   PaintLayer* layer = ToLayoutBox(layout_object_)->Layer();
 

third_party/blink/renderer/platform/exported/web_runtime_features.cc

@@ -716,4 +716,9 @@ void WebRuntimeFeatures::EnableContentIndex(bool enable) {
 void WebRuntimeFeatures::EnableRestrictGamepadAccess(bool enable) {
   RuntimeEnabledFeatures::SetRestrictGamepadAccessEnabled(enable);
 }
+
+void WebRuntimeFeatures::EnableCompositingOptimizations(bool enable) {
+  RuntimeEnabledFeatures::SetCompositingOptimizationsEnabled(enable);
+}
+
 }  // namespace blink

third_party/blink/web_tests/VirtualTestSuites

@@ -107,9 +107,12 @@
               "inspector-protocol/dom-snapshot",
               "media/stable",
               "webexposed",
-              "wpt_internal/origin-isolation"],
+              "wpt_internal/origin-isolation",
+              "compositing/filters"
+              ],
     "args": ["--stable-release-mode",
-             "--disable-auto-wpt-origin-isolation"]
+             "--disable-auto-wpt-origin-isolation",
+             "--enable-blink-features=CompositingOptimizations"]
   },
   {
     "prefix": "feature-policy-permissions",

third_party/blink/web_tests/compositing/filters/sw-nested-shadow-overlaps-hw-nested-shadow-expected.txt

@@ -11,19 +11,6 @@
       "position": [-100, -100],
       "bounds": [200, 200],
       "transform": 1
-    },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV id='software-parent'",
-      "bounds": [100, 100],
-      "contentsOpaque": true,
-      "backgroundColor": "#008000"
-    },
-    {
-      "name": "LayoutNGBlockFlow (positioned) DIV id='software-child'",
-      "position": [100, 100],
-      "bounds": [50, 50],
-      "contentsOpaque": true,
-      "backgroundColor": "#0000FF"
     }
   ],
   "transforms": [

third_party/blink/web_tests/virtual/stable/compositing/filters/README.txt

+Test CompositingOptimizations code paths.

third_party/blink/web_tests/virtual/stable/compositing/filters/sw-nested-shadow-overlaps-hw-nested-shadow-expected.txt

+{
+  "layers": [
+    {
+      "name": "Scrolling Contents Layer",
+      "bounds": [800, 600],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "LayoutNGBlockFlow (positioned) DIV id='composited-parent'",
+      "position": [-100, -100],
+      "bounds": [200, 200],
+      "transform": 1
+    },
+    {
+      "name": "LayoutNGBlockFlow (positioned) DIV id='software-parent'",
+      "bounds": [100, 100],
+      "contentsOpaque": true,
+      "backgroundColor": "#008000"
+    },
+    {
+      "name": "LayoutNGBlockFlow (positioned) DIV id='software-child'",
+      "position": [100, 100],
+      "bounds": [50, 50],
+      "contentsOpaque": true,
+      "backgroundColor": "#0000FF"
+    }
+  ],
+  "transforms": [
+    {
+      "id": 1,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [330, 330, 0, 1]
+      ]
+    }
+  ]
+}
+