Fixed strong mode errors and warnings reachable from lib/observe.dart

benchmark/index.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 observe.test.benchmark.index;
 
 import 'dart:async';
 import 'dart:html';
 import 'package:benchmark_harness/benchmark_harness.dart';
 import 'package:chart/chart.dart';
 import 'package:observe/mirrors_used.dart' as mu; // Makes output smaller.
@@ skipping 37 matching lines @@
 
 final ButtonElement goButton = querySelector('#go');
 final InputElement objectCountInput = querySelector('#objectCountInput');
 final InputElement mutationCountInput = querySelector('#mutationCountInput');
 final SpanElement mutationCountWrapper = querySelector('#mutationCountWrapper');
 final SpanElement statusSpan = querySelector('#status');
 final DivElement canvasWrapper = querySelector('#canvasWrapper');
 final SelectElement benchmarkSelect = querySelector('#benchmarkSelect');
 final SelectElement configSelect = querySelector('#configSelect');
 final UListElement legendList = querySelector('#legendList');
-final List<List<String>> colors = [
+final List<String> colors = [
   [0, 0, 255],
   [138, 43, 226],
   [165, 42, 42],
   [100, 149, 237],
   [220, 20, 60],
   [184, 134, 11]
 ].map((rgb) => 'rgba(' + rgb.join(',') + ',.7)').toList();
 
 main() {
   // TODO(jakemac): Use a transformer to generate the smoke config so we can see
@@ skipping 20 matching lines @@
 
     var i = 0;
     mutationCounts.forEach((count) {
       var li = document.createElement('li');
       li.text = '$count mutations.';
       li.style.color = colors[i % colors.length];
       legendList.append(li);
       i++;
     });
 
-    var results = [];
+    var results = <List<double>>[];
     for (int objectCount in objectCounts) {
       int x = 0;
       for (int mutationCount in mutationCounts) {
         statusSpan.text =
             'Testing: $objectCount objects with $mutationCount mutations';
         // Let the status text render before running the next benchmark.
         await new Future(() {});
         var factory = benchmarkFactories[benchmarkSelect.value];
         var benchmark = factory(objectCount, mutationCount, configSelect.value);
         // Divide by 10 because benchmark_harness returns the amount of time it
@@ skipping 50 matching lines @@
     configSelect.style.display = 'inline';
   }
 
   // Don't show the mutation counts box if running a Setup* benchmark.
   if (benchmarkSelect.value.startsWith('Setup')) {
     mutationCountWrapper.style.display = 'none';
   } else {
     mutationCountWrapper.style.display = 'inline';
   }
 }