Implement matching part of ::slotted() pseudo element

third_party/WebKit/Source/core/css/SelectorFilter.cpp

Index: third_party/WebKit/Source/core/css/SelectorFilter.cpp
diff --git a/third_party/WebKit/Source/core/css/SelectorFilter.cpp b/third_party/WebKit/Source/core/css/SelectorFilter.cpp
index 82863003a1d44c11bb03945fe377ea5c63303b56..edba01dc7abb1a69b8605106a05111159b995f27 100644
--- a/third_party/WebKit/Source/core/css/SelectorFilter.cpp
+++ b/third_party/WebKit/Source/core/css/SelectorFilter.cpp
@@ -134,7 +134,11 @@ void SelectorFilter::collectIdentifierHashes(const CSSSelector& selector, unsign
     unsigned* hash = identifierHashes;
     unsigned* end = identifierHashes + maximumIdentifierCount;
     CSSSelector::Relation relation = selector.relation();
-    bool relationIsAffectedByPseudoContent = selector.relationIsAffectedByPseudoContent();
+    if (selector.relationIsAffectedByPseudoContent()) {
+        // Disable fastRejectSelector.
+        *identifierHashes = 0;
+        return;
+    }
 
     // Skip the topmost selector. It is handled quickly by the rule hashes.
     bool skipOverSubselectors = true;
@@ -149,27 +153,27 @@ void SelectorFilter::collectIdentifierHashes(const CSSSelector& selector, unsign
         case CSSSelector::IndirectAdjacent:
             skipOverSubselectors = true;
             break;
+        case CSSSelector::ShadowSlot:
+            // Disable fastRejectSelector.
+            *identifierHashes = 0;
+            return;
         case CSSSelector::Descendant:
         case CSSSelector::Child:
-            if (relationIsAffectedByPseudoContent) {
-                // Disable fastRejectSelector.
-                *identifierHashes = 0;
-                return;
-            }
             // Fall through.
         case CSSSelector::ShadowPseudo:
         case CSSSelector::ShadowDeep:
             skipOverSubselectors = false;
             collectDescendantSelectorIdentifierHashes(*current, hash);
             break;
-        case CSSSelector::ShadowSlot:
-            // TODO(kochi): Add this in later CL.
-            break;
         }
         if (hash == end)
             return;
         relation = current->relation();
-        relationIsAffectedByPseudoContent = current->relationIsAffectedByPseudoContent();
+        if (current->relationIsAffectedByPseudoContent()) {
+            // Disable fastRejectSelector.
+            *identifierHashes = 0;
+            return;
+        }
     }
     *hash = 0;
 }