Do not re-register cached id-name HTMLCollection at same invalidation type

third_party/WebKit/Source/core/html/HTMLCollection.h

Index: third_party/WebKit/Source/core/html/HTMLCollection.h
diff --git a/third_party/WebKit/Source/core/html/HTMLCollection.h b/third_party/WebKit/Source/core/html/HTMLCollection.h
index 35f4b5496821add31de8cb9673c5afe795c22c86..8ea1e44467c4370966fdf2d03adde76be38448eb 100644
--- a/third_party/WebKit/Source/core/html/HTMLCollection.h
+++ b/third_party/WebKit/Source/core/html/HTMLCollection.h
@@ -117,7 +117,9 @@ protected:
     void setNamedItemCache(PassOwnPtrWillBeRawPtr<NamedItemCache> cache) const
     {
         ASSERT(!m_namedItemCache);
-        document().registerNodeListWithIdNameCache(this);
+        // Do not repeat registration for the same invalidation type.
+        if (invalidationType() != InvalidateOnIdNameAttrChange)
+            document().registerNodeListWithIdNameCache(this);
         m_namedItemCache = std::move(cache);
     }
 
@@ -144,7 +146,9 @@ private:
     void unregisterIdNameCacheFromDocument(Document& document) const
     {
         ASSERT(hasValidIdNameCache());
-        document.unregisterNodeListWithIdNameCache(this);
+        // Do not repeat unregistration for the same invalidation type.
+        if (invalidationType() != InvalidateOnIdNameAttrChange)
+            document.unregisterNodeListWithIdNameCache(this);
     }
 
     const unsigned m_overridesItemAfter : 1;