[inspector] use own copy of third_party/inspector_protocol

third_party/inspector_protocol/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)) { }
+    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) { }
+    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) { }
+    using MaybeBase::operator=;
+};
+
+template<>
+class Maybe<int> : public MaybeBase<int> {
+public:
+    Maybe() { }
+    Maybe(int value) : MaybeBase(value) { }
+    using MaybeBase::operator=;
+};
+
+template<>
+class Maybe<double> : public MaybeBase<double> {
+public:
+    Maybe() { }
+    Maybe(double value) : MaybeBase(value) { }
+    using MaybeBase::operator=;
+};
+
+template<>
+class Maybe<String> : public MaybeBase<String> {
+public:
+    Maybe() { }
+    Maybe(const String& value) : MaybeBase(value) { }
+    using MaybeBase::operator=;
+};
+
+{% for namespace in config.protocol.namespace %}
+} // namespace {{namespace}}
+{% endfor %}
+
+#endif // !defined({{"_".join(config.protocol.namespace)}}_Maybe_h)