Add fast path for tag#id selector queries

Source/core/dom/TreeScope.cpp

Index: Source/core/dom/TreeScope.cpp
diff --git a/Source/core/dom/TreeScope.cpp b/Source/core/dom/TreeScope.cpp
index c624f9df8ca353c1cc77b9445921efda570824a5..e32c8d74f48761954b8a252efb25fda9160fc795 100644
--- a/Source/core/dom/TreeScope.cpp
+++ b/Source/core/dom/TreeScope.cpp
@@ -151,6 +151,15 @@ Element* TreeScope::getElementById(const AtomicString& elementId) const
     return m_elementsById->getElementById(elementId.impl(), this);
 }
 
+const Vector<Element*>* TreeScope::getAllElementsById(const AtomicString& elementId) const
+{
+    if (elementId.isEmpty())
+        return 0;
+    if (!m_elementsById)
+        return 0;
+    return m_elementsById->getAllElementsById(elementId.impl(), this);
+}
+
 void TreeScope::addElementById(const AtomicString& elementId, Element* element)
 {
     if (!m_elementsById)