[DevTools] Migrate v8_inspector/public from String16 to String{View,Buffer}.

third_party/WebKit/Source/platform/v8_inspector/V8StringUtil.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 V8StringUtil_h
 #define V8StringUtil_h
 
 #include "platform/inspector_protocol/InspectorProtocol.h"
 #include "platform/v8_inspector/protocol/Debugger.h"
+#include "platform/v8_inspector/public/StringBuffer.h"
+#include "platform/v8_inspector/public/StringView.h"
 #include <v8.h>
 
 namespace v8_inspector {
 
 class V8InspectorSession;
 
 namespace protocol = blink::protocol;
 
 std::unique_ptr<protocol::Value> toProtocolValue(v8::Local<v8::Context>, v8::Local<v8::Value>, int maxDepth = protocol::Value::maxDepth);
 
 v8::Local<v8::String> toV8String(v8::Isolate*, const String16&);
 v8::Local<v8::String> toV8StringInternalized(v8::Isolate*, const String16&);
 v8::Local<v8::String> toV8StringInternalized(v8::Isolate*, const char*);
+v8::Local<v8::String> toV8String(v8::Isolate*, const StringView&);
 
 String16 toProtocolString(v8::Local<v8::String>);
 String16 toProtocolStringWithTypeCheck(v8::Local<v8::Value>);
+String16 toString16(const StringView&);
+StringView toStringView(const String16&);
+
+bool stringViewStartsWith(const StringView&, const char*);
+std::unique_ptr<protocol::Value> parseJSON(const StringView& json);
 
 String16 findSourceURL(const String16& content, bool multiline);
 String16 findSourceMapURL(const String16& content, bool multiline);
 std::vector<std::unique_ptr<protocol::Debugger::SearchMatch>> searchInTextByLinesImpl(V8InspectorSession*, const String16& text, const String16& query, bool caseSensitive, bool isRegex);
 
+class StringBufferImpl : public StringBuffer {
+    PROTOCOL_DISALLOW_COPY(StringBufferImpl);
+public:
+    // Destroys string's content.
+    static std::unique_ptr<StringBufferImpl> adopt(String16&);
+    const StringView& string() override { return m_string; }
+
+private:
+    explicit StringBufferImpl(String16&);
+    String16 m_owner;
+    StringView m_string;
+};
+
 } //  namespace v8_inspector
 
 
 #endif // !defined(V8StringUtil_h)