Moving platform tracing things into platform/tracing.

third_party/WebKit/Source/platform/TraceEvent.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 TraceEvent_h
-#define TraceEvent_h
-
-#include "base/time/time.h"
-#include "base/trace_event/trace_event.h"
-#include "wtf/text/CString.h"
-
-namespace WTF {
-
-// CString version of SetTraceValue so that trace arguments can be strings.
-static inline void SetTraceValue(const CString& arg,
-                                 unsigned char* type,
-                                 unsigned long long* value) {
-  trace_event_internal::TraceValueUnion typeValue;
-  typeValue.as_string = arg.data();
-  *type = TRACE_VALUE_TYPE_COPY_STRING;
-  *value = typeValue.as_uint;
-}
-
-}  // namespace WTF
-
-namespace blink {
-namespace TraceEvent {
-
-using base::trace_event::TraceScopedTrackableObject;
-
-inline base::TimeTicks toTraceTimestamp(double seconds) {
-  return base::TimeTicks() + base::TimeDelta::FromSecondsD(seconds);
-}
-
-// This is to avoid error of passing a chromium time internal value.
-void toTraceTimestamp(int64_t);
-
-}  // namespace TraceEvent
-}  // namespace blink
-
-#endif