Use dartfmt on Observatory code

runtime/observatory/lib/tracer.dart

 // Copyright (c) 2013, 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.
 
 library tracer;
 
 import 'dart:async';
 
 import 'package:logging/logging.dart';
 import 'package:observe/observe.dart';
 
 _deepCopy(src) {
   if (src is Map) {
     var dest = {};
     src.forEach((key, val) {
-        dest[key] = _deepCopy(val);
+      dest[key] = _deepCopy(val);
     });
     return dest;
   } else if (src is List) {
     var dest = [];
     src.forEach((val) {
-        dest.add(_deepCopy(val));
+      dest.add(_deepCopy(val));
     });
     return dest;
   } else {
     return src;
   }
 }
 
 class TraceEvent {
   TraceEvent.msg(this._time, this.message, Map originalMap) {
     map = _deepCopy(originalMap);
@@ skipping 14 matching lines @@
   // The current global tracer.
   static Tracer get current => _current;
 
   static Tracer _current;
 
   static void start() {
     if (_current == null) {
       _current = new Tracer();
     }
   }
+
   static void stop() {
     if (_current != null) {
       _current.cancel();
       _current = null;
     }
   }
 
   // The tracer subscribes to all logging events.
   StreamSubscription loggerSub = null;
 
   // The start time for the current request.
   Stopwatch _time;
 
   // A list of all tracing events for thre current request.
   ObservableList<TraceEvent> events = new ObservableList<TraceEvent>();
 
   Tracer() {
     _time = new Stopwatch();
     _time.start();
     loggerSub = Logger.root.onRecord.listen((LogRecord rec) {
-        // Echo all log messages to the trace.
-        trace('${rec.level.name}: ${rec.message}');
-      });
+      // Echo all log messages to the trace.
+      trace('${rec.level.name}: ${rec.message}');
+    });
     reset();
   }
 
   void cancel() {
     loggerSub.cancel();
   }
 
   void reset() {
     _time.reset();
     events.clear();
   }
 
   TraceEvent trace(String message, {Map map: null}) {
     var event = new TraceEvent.msg(_time.elapsedMicroseconds, message, map);
     events.add(event);
     return event;
   }
 }