Fix all strong mode warnings in protoc-plugin

benchmark/lib/dashboard_view.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.html_view;
 
 import 'dart:async' show Stream, StreamController, EventSink;
 import 'dart:html';
 
 import 'generated/benchmark.pb.dart' as pb;
@@ skipping 55 matching lines @@
       this._runButton,
       this._selectAllButton,
       this._selectNoneButton,
       this._status,
       this._envElt,
       this._menu,
       this._responseTable,
       this._jsonView);
 
   factory DashboardView() {
-    var elt = _template.clone(true);
+    Element elt = _template.clone(true);
     find(String q) => elt.querySelector(q);
     _Button button(q) => new _Button(find(q));
     label(q) => new _Label(find(q));
     menu(q) => new _Menu(find(q));
     json(q) => new _JsonView(find(q));
     return new DashboardView._raw(
         elt,
         button('.dv-run')
           ..elt.style.color = "#FFFFFF"
           ..elt.style.backgroundColor = "rgb(209, 72, 64)",
         button('.dv-select-all'),
         button('.dv-select-none'),
         label('.dv-status'),
         find('.dv-env'),
         menu('.dv-menu'),
         find('.dv-table'),
         json('.dv-json'));
   }
 
   Stream get onRunButtonClick => _runButton.onClick;
   Stream get onSelectAllClick => _selectAllButton.onClick;
   Stream get onSelectNoneClick => _selectNoneButton.onClick;
   Stream<String> get onMenuChange =>
-    _menu.onChange.map((item) => item == noBaseline ? null : item);
+      _menu.onChange.map((item) => item == noBaseline ? null : item);
   Stream<SelectEvent<pb.Request>> get onSelectionChange =>
       _selectionChanges.stream;
 
   void render(DashboardModel model) {
     _runButton.render("Run", model.canRun);
     _selectAllButton.render("Select All", true);
     _selectNoneButton.render("Select None", true);
     if (!model.latest.hasStatus() || model.latest.status == pb.Status.DONE) {
       _status.render("");
     } else {
@@ skipping 58 matching lines @@
       _selected.elt,
       _summary.elt,
       _baseline.elt,
       _median.elt,
       _max.elt,
       _count.elt,
       _units.elt
     ]);
   }
 
-  void render(Row row, pb.Report r,
-      EventSink<SelectEvent<pb.Request>> rowSelected) {
+  void render(
+      Row row, pb.Report r, EventSink<SelectEvent<pb.Request>> rowSelected) {
     var b = row.benchmark;
     var response = row.findResponse(r);
     _selected.render(row.selected, item: row.request, sink: rowSelected);
     _summary.render(b.summary);
     _baseline.render(b.measureSample(row.baseline));
     _median.render(b.measureSample(b.medianSample(response)));
     _max.render(b.measureSample(b.maxSample(response)));
     _count.render(response == null ? "0" : "${response.samples.length}");
     _units.render(row.benchmark.measureSampleUnits);
   }
@@ skipping 37 matching lines @@
       new HeadingElement.h2()..text = "Report data as JSON:",
       new PreElement()..text = json
     ]);
     _rendered = json;
   }
 }
 
 /// A menu of selectable text items.
 class _Menu {
   final SelectElement elt;
-  final _changes = new StreamController.broadcast();
+  final _changes = new StreamController<String>.broadcast();
   final _options = new List<_MenuOption>();
 
   _Menu(this.elt) {
     elt.onChange.listen((e) => _changes.add(elt.value));
   }
 
   Stream<String> get onChange => _changes.stream;
 
   void render(List<String> items, String selected) {
     var it = items.iterator;
@@ skipping 86 matching lines @@
 
   void render(bool checked, {EventSink<SelectEvent<T>> sink, T item}) {
     if (_renderedChecked != checked) {
       elt.checked = checked;
       _renderedChecked = checked;
     }
     _item = item;
     _sink = sink;
   }
 }