Describe .nc files as "No Compile Test" suites and link doc.

base/memory/scoped_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/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/ref_counted.h"
 
 namespace {
 
 class Parent {
 };
 
 class Child : public Parent {
@@ skipping 89 matching lines @@
 // support would require changes to the behavior of the constructors to match
 // including the use of SFINAE to discard the type-converting constructor
 // as per C++11 20.7.1.2.1.19.
 void WontCompile() {
   Deleter d;
   int n;
   scoped_ptr<int*, Deleter&> a(&n, d);
 }
 
 #endif