[inspector_protocol] support fall through and moveable Maybe

lib/Maybe_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)}}_Maybe_h
 #define {{"_".join(config.protocol.namespace)}}_Maybe_h
 
 //#include "Forward.h"
 
 {% for namespace in config.protocol.namespace %}
 namespace {{namespace}} {
 {% endfor %}
 
 template<typename T>
 class Maybe {
 public:
     Maybe() : m_value() { }
     Maybe(std::unique_ptr<T> value) : m_value(std::move(value)) { }
+    Maybe(Maybe&& other) : m_value(std::move(other.m_value)) { }
     void operator=(std::unique_ptr<T> value) { m_value = std::move(value); }
     T* fromJust() const { DCHECK(m_value); return m_value.get(); }
     T* fromMaybe(T* defaultValue) const { return m_value ? m_value.get() : defaultValue; }
     bool isJust() const { return !!m_value; }
     std::unique_ptr<T> takeJust() { DCHECK(m_value); return m_value.release(); }
 private:
     std::unique_ptr<T> m_value;
 };
 
 template<typename T>
 class MaybeBase {
 public:
     MaybeBase() : m_isJust(false) { }
     MaybeBase(T value) : m_isJust(true), m_value(value) { }
+    MaybeBase(MaybeBase&& other) : m_isJust(other.m_isJust), m_value(std::move(other.m_value)) { }
     void operator=(T value) { m_value = value; m_isJust = true; }
     T fromJust() const { DCHECK(m_isJust); return m_value; }
     T fromMaybe(const T& defaultValue) const { return m_isJust ? m_value : defaultValue; }
     bool isJust() const { return m_isJust; }
     T takeJust() { DCHECK(m_isJust); return m_value; }
 
 protected:
     bool m_isJust;
     T m_value;
 };
 
 template<>
 class Maybe<bool> : public MaybeBase<bool> {
 public:
     Maybe() { }
     Maybe(bool value) : MaybeBase(value) { }
+    Maybe(Maybe&& other) : MaybeBase(std::move(other)) { }
     using MaybeBase::operator=;
 };
 
 template<>
 class Maybe<int> : public MaybeBase<int> {
 public:
     Maybe() { }
     Maybe(int value) : MaybeBase(value) { }
+    Maybe(Maybe&& other) : MaybeBase(std::move(other)) { }
     using MaybeBase::operator=;
 };
 
 template<>
 class Maybe<double> : public MaybeBase<double> {
 public:
     Maybe() { }
     Maybe(double value) : MaybeBase(value) { }
+    Maybe(Maybe&& other) : MaybeBase(std::move(other)) { }
     using MaybeBase::operator=;
 };
 
 template<>
 class Maybe<String> : public MaybeBase<String> {
 public:
     Maybe() { }
     Maybe(const String& value) : MaybeBase(value) { }
+    Maybe(Maybe&& other) : MaybeBase(std::move(other)) { }
     using MaybeBase::operator=;
 };
 
 {% for namespace in config.protocol.namespace %}
 } // namespace {{namespace}}
 {% endfor %}
 
 #endif // !defined({{"_".join(config.protocol.namespace)}}_Maybe_h)