Update weak_ptr_unittest.nc expectation

base/memory/weak_ptr_unittest.nc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This is a "No Compile Test" suite.
 // http://dev.chromium.org/developers/testing/no-compile-tests
 
 #include "base/memory/weak_ptr.h"
 
 namespace base {
@@ skipping 111 matching lines @@
   WeakPtr<Unrelated> ptr = AsWeakPtr(&f);
 }
 
 #elif defined(NCTEST_DERIVED_COMPLETELY_UNRELATED_HELPER)  // [r"fatal error: static_assert failed \"AsWeakPtr argument must inherit from SupportsWeakPtr\""]
 
 void WontCompile() {
   DerivedUnrelated f;
   WeakPtr<Unrelated> ptr = AsWeakPtr(&f);
 }
 
-#elif defined(NCTEST_AMBIGUOUS_ANCESTORS)  // [r"fatal error: member 'AsWeakPtr' found in multiple base classes of different types"]
+#elif defined(NCTEST_AMBIGUOUS_ANCESTORS)  // [r"fatal error: use of undeclared identifier 'AsWeakPtrImpl'"]
 
 void WontCompile() {
   MultiplyDerivedProducer f;
   WeakPtr<MultiplyDerivedProducer> ptr = AsWeakPtr(&f);
 }
 
 #endif
 
 }