Fix all strong mode warnings in protoc-plugin

benchmark/lib/dashboard_model.dart

 // 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.
 
 library protoc.benchmark.dashboard_model;
 
 import 'generated/benchmark.pb.dart' as pb;
 
 import 'benchmark.dart' show Benchmark;
 import 'benchmarks/index.dart' show createBenchmark;
@@ skipping 22 matching lines @@
 }
 
 /// The parts of the benchmark results table that don't change often.
 class Table {
   final pb.Suite suite;
   final String baseline;
   final pb.Report report;
   final Set<pb.Request> selections;
   final rows = <Row>[];
 
-  factory Table(pb.Suite suite) =>
-    new Table._raw(suite, null, null, new Set<pb.Request>.from(suite.requests));
+  factory Table(pb.Suite suite) => new Table._raw(
+      suite, null, null, new Set<pb.Request>.from(suite.requests));
 
   Table._raw(this.suite, this.baseline, this.report, this.selections) {
-    var it = report == null ? [].iterator : report.responses.iterator;
+    Iterator it = report == null ? [].iterator : report.responses.iterator;
     for (var r in suite.requests) {
       var b = createBenchmark(r);
       pb.Sample baseline;
       if (it.moveNext()) {
         b.checkRequest(it.current.request);
         baseline = b.medianSample(it.current);
       }
       rows.add(new Row(r, b, baseline, selected: this.selections.contains(r)));
     }
   }
 
   Table withBaseline(String baseline, pb.Report report) =>
       new Table._raw(suite, baseline, report, selections);
 
   Table withAllSelected() {
-    return new Table._raw(suite, baseline, report,
-      new Set<pb.Request>.from(suite.requests));
+    return new Table._raw(
+        suite, baseline, report, new Set<pb.Request>.from(suite.requests));
   }
 
   Table withNoneSelected() {
     return new Table._raw(suite, baseline, report, new Set<pb.Request>());
   }
 
   Table withSelection(pb.Request request, bool selected) {
     var s = new Set<pb.Request>.from(selections);
     if (selected) {
       s.add(request);
@@ skipping 21 matching lines @@
   }
 }
 
 // Indicates that the given item was added or removed from a selection.
 class SelectEvent<T> {
   final bool selected;
   final T item;
   SelectEvent(this.selected, [this.item]);
   toString() => "SelectEvent($selected, $item)";
 }