Skip child ShadowRoots when invalidation does not have boundary crossing rules

Source/core/css/invalidation/DescendantInvalidationSet.cpp

Index: Source/core/css/invalidation/DescendantInvalidationSet.cpp
diff --git a/Source/core/css/invalidation/DescendantInvalidationSet.cpp b/Source/core/css/invalidation/DescendantInvalidationSet.cpp
index e7122a939d0f87296afb02159f55c49d09dab881..6f1be3b13bf3acc04cbc21124ea902456e9ea2d7 100644
--- a/Source/core/css/invalidation/DescendantInvalidationSet.cpp
+++ b/Source/core/css/invalidation/DescendantInvalidationSet.cpp
@@ -39,6 +39,7 @@ namespace WebCore {
 DescendantInvalidationSet::DescendantInvalidationSet()
     : m_allDescendantsMightBeInvalid(false)
     , m_customPseudoInvalid(false)
+    , m_treeBoundaryCrossing(false)
 {
 }
 
@@ -85,6 +86,9 @@ void DescendantInvalidationSet::combine(const DescendantInvalidationSet& other)
     if (other.customPseudoInvalid())
         setCustomPseudoInvalid();
 
+    if (other.treeBoundaryCrossing())
+        setTreeBoundaryCrossing();
+
     if (other.m_classes) {
         WillBeHeapHashSet<AtomicString>::const_iterator end = other.m_classes->end();
         for (WillBeHeapHashSet<AtomicString>::const_iterator it = other.m_classes->begin(); it != end; ++it)
@@ -172,6 +176,7 @@ void DescendantInvalidationSet::setWholeSubtreeInvalid()
         return;
 
     m_allDescendantsMightBeInvalid = true;
+    m_treeBoundaryCrossing = false;
     m_classes = nullptr;
     m_ids = nullptr;
     m_tagNames = nullptr;