Make base::Value::TYPE a scoped enum.

tools/gn/command_desc.cc

 // Copyright (c) 2013 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 <stddef.h>
 
 #include <algorithm>
 #include <set>
 #include <sstream>
 
@@ skipping 38 matching lines @@
     OutputString(indent);
     OutputString(bool_value ? "true" : "false");
     OutputString("\n");
   } else if (value->GetAsDictionary(&dict_value)) {
     base::DictionaryValue::Iterator iter(*dict_value);
     while (!iter.IsAtEnd()) {
       OutputString(indent + iter.key() + "\n");
       PrintValue(&iter.value(), indentLevel + 1);
       iter.Advance();
     }
-  } else if (value->IsType(base::Value::TYPE_NULL)) {
+  } else if (value->IsType(base::Value::Type::NONE)) {
     OutputString(indent + "<null>\n");
   }
 }
 
 // Default handler for property
 void DefaultHandler(const std::string& name, const base::Value* value) {
   OutputString("\n");
   OutputString(name);
   OutputString("\n");
   PrintValue(value, 1);
@@ skipping 430 matching lines @@
 
       if (!PrintConfig(config, what_to_print, !multiple_outputs))
         return 1;
     }
   }
 
   return 0;
 }
 
 }  // namespace commands