- Change "static final" to "static const" in the lib/ directory.

lib/html/src/Measurement.dart

 // Copyright (c) 2012, 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.
 
 typedef Object ComputeValue();
 
 class _MeasurementRequest<T> {
   final ComputeValue computeValue;
   final Completer<T> completer;
   Object value;
   bool exception = false;
   _MeasurementRequest(this.computeValue, this.completer);
 }
 
-final _MEASUREMENT_MESSAGE = "DART-MEASURE";
+const _MEASUREMENT_MESSAGE = "DART-MEASURE";
 List<_MeasurementRequest> _pendingRequests;
 List<TimeoutHandler> _pendingMeasurementFrameCallbacks;
 bool _nextMeasurementFrameScheduled = false;
 bool _firstMeasurementRequest = true;
 
 void _maybeScheduleMeasurementFrame() {
   if (_nextMeasurementFrameScheduled) return;
 
   _nextMeasurementFrameScheduled = true;
   // postMessage gives us a way to receive a callback after the current
@@ skipping 85 matching lines @@
     }
   }
 
   if (readyMeasurementFrameCallbacks !== null) {
     for (TimeoutHandler handler in readyMeasurementFrameCallbacks) {
       // TODO(jacobr): wrap each call to a handler in a try-catch block.
       handler();
     }
   }
 }