Support a negation pseudo-class, :not(), in <content select>

Source/core/testing/InternalSettings.cpp

Index: Source/core/testing/InternalSettings.cpp
diff --git a/Source/core/testing/InternalSettings.cpp b/Source/core/testing/InternalSettings.cpp
index 0ae8d8e51c3d77d5c78f87d947e7182ac2e7fc6c..a5dd5d36c1c4607d8edf9fcc4d90cd80d9b16627 100644
--- a/Source/core/testing/InternalSettings.cpp
+++ b/Source/core/testing/InternalSettings.cpp
@@ -73,6 +73,7 @@ InternalSettings::Backup::Backup(Settings* settings)
     , m_imagesEnabled(settings->imagesEnabled())
     , m_defaultVideoPosterURL(settings->defaultVideoPosterURL())
     , m_originalLayerSquashingEnabled(settings->layerSquashingEnabled())
+    , m_originalPseudoClassesInMatchingCriteriaInAuthorShadowTreesEnabled(RuntimeEnabledFeatures::pseudoClassesInMatchingCriteriaInAuthorShadowTreesEnabled())
 {
 }
 
@@ -94,6 +95,7 @@ void InternalSettings::Backup::restoreTo(Settings* settings)
     settings->setDefaultVideoPosterURL(m_defaultVideoPosterURL);
     settings->setLayerSquashingEnabled(m_originalLayerSquashingEnabled);
     settings->genericFontFamilySettings().reset();
+    RuntimeEnabledFeatures::setPseudoClassesInMatchingCriteriaInAuthorShadowTreesEnabled(m_originalPseudoClassesInMatchingCriteriaInAuthorShadowTreesEnabled);
 }
 
 #if ENABLE(OILPAN)
@@ -184,6 +186,11 @@ void InternalSettings::setExperimentalContentSecurityPolicyFeaturesEnabled(bool
     RuntimeEnabledFeatures::setExperimentalContentSecurityPolicyFeaturesEnabled(enabled);
 }
 
+void InternalSettings::setPseudoClassesInMatchingCriteriaInAuthorShadowTreesEnabled(bool enabled)
+{
+    RuntimeEnabledFeatures::setPseudoClassesInMatchingCriteriaInAuthorShadowTreesEnabled(enabled);
+}
+
 void InternalSettings::setOverlayScrollbarsEnabled(bool enabled)
 {
     RuntimeEnabledFeatures::setOverlayScrollbarsEnabled(enabled);