net: Add NET_API to net/base

base/threading/non_thread_safe.h

 // Copyright (c) 2011 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.
 
 #ifndef BASE_THREADING_NON_THREAD_SAFE_H_
 #define BASE_THREADING_NON_THREAD_SAFE_H_
 #pragma once
 
+// Classes deriving from NonThreadSafe may need to supress MSVC warning 4275:
+// non dll-interface class 'Bar' used as base for dll-interface class 'Foo'.
+// There is a specific macro to do it: NON_EXPORTED_BASE(), defined in
+// compiler_specific.h
+#include "base/compiler_specific.h"
+
 #ifndef NDEBUG
 #include "base/threading/non_thread_safe_impl.h"
 #endif
 
 namespace base {
 
 // Do nothing implementation of NonThreadSafe, for release mode.
 //
 // Note: You should almost always use the NonThreadSafe class to get
 // the right version of the class for your build configuration.
@@ skipping 29 matching lines @@
 class NonThreadSafe : public NonThreadSafeImpl {
 };
 #else
 class NonThreadSafe : public NonThreadSafeDoNothing {
 };
 #endif  // NDEBUG
 
 }  // namespace base
 
 #endif  // BASE_NON_THREAD_SAFE_H_