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

third_party/WebKit/Source/platform/v8_inspector/V8StackTraceImpl.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 V8StackTraceImpl_h
 #define V8StackTraceImpl_h
 
 #include "platform/inspector_protocol/InspectorProtocol.h"
 #include "platform/v8_inspector/protocol/Runtime.h"
 #include "platform/v8_inspector/public/V8StackTrace.h"
@@ skipping 46 matching lines @@
 
     // This method drops the async chain. Use cloneImpl() instead.
     std::unique_ptr<V8StackTrace> clone() override;
     std::unique_ptr<V8StackTraceImpl> cloneImpl();
     std::unique_ptr<protocol::Runtime::StackTrace> buildInspectorObjectForTail(V8Debugger*) const;
     std::unique_ptr<protocol::Runtime::StackTrace> buildInspectorObjectImpl() const;
     ~V8StackTraceImpl() override;
 
     // V8StackTrace implementation.
     bool isEmpty() const override { return !m_frames.size(); };
-    String16 topSourceURL() const override;
+    StringView topSourceURL() const override;
     int topLineNumber() const override;
     int topColumnNumber() const override;
-    String16 topScriptId() const override;
-    String16 topFunctionName() const override;
+    StringView topScriptId() const override;
+    StringView topFunctionName() const override;
     std::unique_ptr<protocol::Runtime::API::StackTrace> buildInspectorObject() const override;
-    String16 toString() const override;
+    std::unique_ptr<StringBuffer> toString() const override;
 
 private:
     V8StackTraceImpl(int contextGroupId, const String16& description, std::vector<Frame>& frames, std::unique_ptr<V8StackTraceImpl> parent);
 
     int m_contextGroupId;
     String16 m_description;
     std::vector<Frame> m_frames;
     std::unique_ptr<V8StackTraceImpl> m_parent;
 };
 
 } // namespace v8_inspector
 
 #endif // V8StackTraceImpl_h