Move both instances of address_of into stl_util.

base/stl_util.h

Index: base/stl_util.h
diff --git a/base/stl_util.h b/base/stl_util.h
index af77150f6b3a83d6d8081b7182492c0a7c021ac4..6338c7ef7844867e193190e293a61a113e73b6b7 100644
--- a/base/stl_util.h
+++ b/base/stl_util.h
@@ -11,6 +11,19 @@
 #include <string>
 #include <vector>
 
+// Return the address of an object as a unary functor.
+// Can be used with std::transform to make a container of pointers from a
+// container of objects.
+// NOTE: Does not work around the possibility that operator & is overloaded.
+template<typename T>
+T* address_of(T& v) {
+  return &v;
+}
+template<typename T>
+const T* const_address_of(const T& v) {
+  return &v;
+}
+
 // Clear internal memory of an STL object.
 // STL clear()/reserve(0) does not always free internal memory allocated
 // This function uses swap/destructor to ensure the internal memory is freed.