Use real process and thread ids when outputting trace-event

runtime/vm/timeline.h

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_TIMELINE_H_
 #define VM_TIMELINE_H_
 
 #include "vm/bitfield.h"
 
 namespace dart {
@@ skipping 78 matching lines @@
     char* value;
   };
 
   int64_t timestamp0_;
   int64_t timestamp1_;
   TimelineEventArgument* arguments_;
   intptr_t arguments_length_;
   uword state_;
   const char* label_;
   TimelineStream* stream_;
-  Thread* thread_;
+  ThreadId thread_;
 
   void FreeArguments();
 
   void StreamInit(TimelineStream* stream);
   void Init(EventType event_type, const char* label);
 
   void set_event_type(EventType event_type) {
     state_ = EventTypeField::update(event_type, state_);
   }
 
@@ skipping 305 matching lines @@
   TimelineEventBlock* GetNewBlockLocked();
   void PrintJSONEvents(JSONArray* array) const;
 
   Mutex lock_;
   TimelineEventBlock* head_;
 };
 
 }  // namespace dart
 
 #endif  // VM_TIMELINE_H_