Moving platform tracing things into platform/tracing.

third_party/WebKit/Source/platform/TracedValue.h

-// Copyright 2014 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 TracedValue_h
-#define TracedValue_h
-
-#include "base/memory/ref_counted.h"
-#include "platform/EventTracer.h"
-#include "wtf/text/WTFString.h"
-#include <memory>
-
-namespace base {
-namespace trace_event {
-class TracedValue;
-}
-}
-
-namespace blink {
-
-// TracedValue copies all passed names and values and doesn't retain references.
-class PLATFORM_EXPORT TracedValue final {
-    WTF_MAKE_NONCOPYABLE(TracedValue);
-
-public:
-    ~TracedValue();
-
-    static std::unique_ptr<TracedValue> create();
-
-    void endDictionary();
-    void endArray();
-
-    void setInteger(const char* name, int value);
-    void setDouble(const char* name, double);
-    void setBoolean(const char* name, bool value);
-    void setString(const char* name, const String& value);
-    void beginArray(const char* name);
-    void beginDictionary(const char* name);
-
-    void pushInteger(int);
-    void pushDouble(double);
-    void pushBoolean(bool);
-    void pushString(const String&);
-    void beginArray();
-    void beginDictionary();
-
-    String toString() const;
-
-private:
-    TracedValue();
-
-    // This will be moved (and become null) when TracedValue is passed to
-    // EventTracer::addTraceEvent().
-    std::unique_ptr<base::trace_event::TracedValue> m_tracedValue;
-
-    friend class EventTracer;
-};
-
-} // namespace blink
-
-#endif // TracedValue_h