Mark the AtomicString(const String&) constructor as explicit

Source/core/xml/XPathFunctions.cpp

Index: Source/core/xml/XPathFunctions.cpp
diff --git a/Source/core/xml/XPathFunctions.cpp b/Source/core/xml/XPathFunctions.cpp
index 978d858b6bbf41f1887dd71a8adbb8536873e82b..d0da20d667db488f9fab1ac2e3a07dbc6147ee6b 100644
--- a/Source/core/xml/XPathFunctions.cpp
+++ b/Source/core/xml/XPathFunctions.cpp
@@ -349,7 +349,7 @@ Value FunId::evaluate() const
 
         // If there are several nodes with the same id, id() should return the first one.
         // In WebKit, getElementById behaves so, too, although its behavior in this case is formally undefined.
-        Node* node = contextScope.getElementById(idList.substring(startPos, endPos - startPos));
+        Node* node = contextScope.getElementById(AtomicString(idList.substring(startPos, endPos - startPos)));
         if (node && resultSet.add(node).isNewEntry)
             result.append(node);