Implemented mid-level Negotiate protocol for Posix.

base/native_library_mac.mm

 // Copyright (c) 2009 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.
 
 #include "base/native_library.h"
 
 #include <dlfcn.h>
 #import <Carbon/Carbon.h>
 
 #include "base/file_path.h"
@@ skipping 55 matching lines @@
     return CFBundleGetFunctionPointerForName(library->bundle, symbol_name);
   }
   return dlsym(library->dylib, name);
 }
 
 // static
 string16 GetNativeLibraryName(const string16& name) {
   return name + ASCIIToUTF16(".dylib");
 }
 
+string16 GetLibraryErrorMessage() {
+  const char* last_err_message = dlerror();
+  string16 err_message;
+
+  if (last_err_message) {
+    err_message = ASCIIToUTF16(last_err_message);
+  }
+
+  return err_message;
+}
+
 }  // namespace base