Revert "Remove OwnPtr from Blink."

third_party/WebKit/Source/platform/TraceEventCommon.h

 // Copyright 2015 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.
 
 // This header file defines the set of trace_event macros without specifying
 // how the events actually get collected and stored. If you need to expose trace
 // events to some other universe, you can copy-and-paste this file as well as
 // trace_event.h, modifying the macros contained there as necessary for the
 // target platform. The end result is that multiple libraries can funnel events
 // through to a shared trace event collector.
@@ skipping 130 matching lines @@
 // the way we estimate tracing memory overhead. All objects passed to the
 // tracing framework should be allocated by malloc to calculate overhead
 // correctly, while many Blink objects use PartitionAlloc/Oilpan. Convertable
 // is an interface to avoid unnecessary conversion but if we allow to use
 // PartitionAlloc/Oilpan backed objects, overhead estimation could be wrong.
 // For structured objects, you can use TracedValue.
 //
 //   class MyData {
 //    public:
 //     MyData() {}
-//     std::unique_ptr<TracedValue> toTracedValue() {
-//       std::unique_ptr<TracedValue> tracedValue = TracedValue::create();
+//     PassOwnPtr<TracedValue> toTracedValue() {
+//       OwnPtr<TracedValue> tracedValue = TracedValue::create();
 //       tracedValue->setInteger("foo", 1);
 //       tracedValue->beginArray("bar");
 //       tracedValue->pushInteger(2);
 //       tracedValue->pushInteger(3);
 //       tracedValue->endArray();
 //       return tracedValue.release();
 //     }
 //    private:
 //     ~MyData() override {}
 //   };
@@ skipping 886 matching lines @@
 
 // Enum reflecting the scope of an INSTANT event. Must fit within
 // TRACE_EVENT_FLAG_SCOPE_MASK.
 #define TRACE_EVENT_SCOPE_GLOBAL (static_cast<unsigned char>(0 << 3))
 #define TRACE_EVENT_SCOPE_PROCESS (static_cast<unsigned char>(1 << 3))
 #define TRACE_EVENT_SCOPE_THREAD (static_cast<unsigned char>(2 << 3))
 
 #define TRACE_EVENT_SCOPE_NAME_GLOBAL ('g')
 #define TRACE_EVENT_SCOPE_NAME_PROCESS ('p')
 #define TRACE_EVENT_SCOPE_NAME_THREAD ('t')