[DevTools] Reduce API surface of String16.

third_party/WebKit/Source/platform/inspector_protocol/Maybe.h

 // 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 Maybe_h
 #define Maybe_h
 
 #include "platform/inspector_protocol/Platform.h"
 #include "platform/inspector_protocol/String16.h"
 
 #include <memory>
 
 namespace blink {
 namespace protocol {
 
-class String16;
-
 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(); }
@@ skipping 35 matching lines @@
 
 template<>
 class Maybe<double> : public MaybeBase<double> {
 public:
     Maybe() { }
     Maybe(double value) : MaybeBase(value) { }
     using MaybeBase::operator=;
 };
 
 template<>
-class Maybe<String> : public MaybeBase<String> {
+class Maybe<InspectorProtocolConvenienceStringType> : public MaybeBase<InspectorProtocolConvenienceStringType> {
 public:
     Maybe() { }
-    Maybe(const String& value) : MaybeBase(value) { }
+    Maybe(const InspectorProtocolConvenienceStringType& value) : MaybeBase(value) { }
     using MaybeBase::operator=;
 };
 
 template<>
 class Maybe<String16> : public MaybeBase<String16> {
 public:
     Maybe() { }
     Maybe(const String16& value) : MaybeBase(value) { }
     using MaybeBase::operator=;
 };
 
 } // namespace platform
 } // namespace blink
 
 #endif // !defined(Maybe_h)