[inspector_protocol] Introduce protocol::Serializable

lib/Values_h.template

 // Copyright 2016 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 {{"_".join(config.protocol.namespace)}}_Values_h
 #define {{"_".join(config.protocol.namespace)}}_Values_h
 
 //#include "Allocator.h"
 //#include "Collections.h"
 //#include "Forward.h"
 
 {% for namespace in config.protocol.namespace %}
 namespace {{namespace}} {
 {% endfor %}
 
 class ListValue;
 class DictionaryValue;
 class Value;
 
-class {{config.lib.export_macro}} Value {
+class {{config.lib.export_macro}} Value : public Serializable {
     PROTOCOL_DISALLOW_COPY(Value);
 public:
-    virtual ~Value() { }
+    virtual ~Value() override { }
 
     static std::unique_ptr<Value> null()
     {
         return std::unique_ptr<Value>(new Value());
     }
 
     enum ValueType {
         TypeNull = 0,
         TypeBoolean,
         TypeInteger,
         TypeDouble,
         TypeString,
         TypeObject,
         TypeArray,
         TypeSerialized
     };
 
     ValueType type() const { return m_type; }
 
     bool isNull() const { return m_type == TypeNull; }
 
     virtual bool asBoolean(bool* output) const;
     virtual bool asDouble(double* output) const;
     virtual bool asInteger(int* output) const;
     virtual bool asString(String* output) const;
     virtual bool asSerialized(String* output) const;
 
-    String toJSONString() const;
     virtual void writeJSON(StringBuilder* output) const;
     virtual std::unique_ptr<Value> clone() const;
+    String serialize() override;
 
 protected:
     Value() : m_type(TypeNull) { }
     explicit Value(ValueType type) : m_type(type) { }
 
 private:
     friend class DictionaryValue;
     friend class ListValue;
 
     ValueType m_type;
@@ skipping 173 matching lines @@
 private:
     ListValue();
     std::vector<std::unique_ptr<Value>> m_data;
 };
 
 {% for namespace in config.protocol.namespace %}
 } // namespace {{namespace}}
 {% endfor %}
 
 #endif // {{"_".join(config.protocol.namespace)}}_Values_h