fix(ddc): router, compiler, web worker fixes for DDC

Also enable DDC checks across all non-web worker playground apps. We are
now down to 2 DDC errors across all of them. The remaining two need to be
fixed in package:analyzer, not in angular.

BREAKING CHANGE:

- there's a chance of breakage as router's Instruction constructor
  signature changed.

Closes #6693

modules/angular2/src/compiler/template_normalizer.ts

@@ -112,6 +112,10 @@ class TemplatePreparseVisitor implements HtmlAstVisitor {
       case PreparsedElementType.STYLESHEET:
         this.styleUrls.push(preparsedElement.hrefAttr);
         break;
+      default:
+        // DDC reports this as error. See:
+        // https://github.com/dart-lang/dev_compiler/issues/428
+        break;
     }
     if (preparsedElement.nonBindable) {
       this.ngNonBindableStackCount++;

modules/angular2/src/router/instruction.ts

@@ -107,9 +107,8 @@ export var BLANK_ROUTE_DATA = new RouteData();
  * ```
  */
 export abstract class Instruction {
-  public component: ComponentInstruction;
-  public child: Instruction;
-  public auxInstruction: {[key: string]: Instruction} = {};
+  constructor(public component: ComponentInstruction, public child: Instruction,
+              public auxInstruction: {[key: string]: Instruction}) {}
 
   get urlPath(): string { return isPresent(this.component) ? this.component.urlPath : ''; }
 
@@ -210,9 +209,9 @@ export abstract class Instruction {
  * a resolved instruction has an outlet instruction for itself, but maybe not for...
  */
 export class ResolvedInstruction extends Instruction {
-  constructor(public component: ComponentInstruction, public child: Instruction,
-              public auxInstruction: {[key: string]: Instruction}) {
-    super();
+  constructor(component: ComponentInstruction, child: Instruction,
+              auxInstruction: {[key: string]: Instruction}) {
+    super(component, child, auxInstruction);
   }
 
   resolveComponent(): Promise<ComponentInstruction> {
@@ -225,7 +224,9 @@ export class ResolvedInstruction extends Instruction {
  * Represents a resolved default route
  */
 export class DefaultInstruction extends Instruction {
-  constructor(public component: ComponentInstruction, public child: DefaultInstruction) { super(); }
+  constructor(component: ComponentInstruction, child: DefaultInstruction) {
+    super(component, child, {});
+  }
 
   resolveComponent(): Promise<ComponentInstruction> {
     return PromiseWrapper.resolve(this.component);
@@ -244,7 +245,7 @@ export class DefaultInstruction extends Instruction {
 export class UnresolvedInstruction extends Instruction {
   constructor(private _resolver: () => Promise<Instruction>, private _urlPath: string = '',
               private _urlParams: string[] = CONST_EXPR([])) {
-    super();
+    super(null, null, {});
   }
 
   get urlPath(): string {

modules/angular2/src/router/router.ts

@@ -202,12 +202,12 @@ export class Router {
     return this._settleInstruction(instruction)
         .then((_) => this._routerCanReuse(instruction))
         .then((_) => this._canActivate(instruction))
-        .then((result) => {
+        .then((result: boolean) => {
           if (!result) {
             return false;
           }
           return this._routerCanDeactivate(instruction)
-              .then((result) => {
+              .then((result: boolean) => {
                 if (result) {
                   return this.commit(instruction, _skipLocationChange)
                       .then((_) => {

modules/angular2/src/web_workers/shared/generic_message_bus.dart

@@ -9,29 +9,32 @@ import 'package:angular2/src/facade/lang.dart';
 import 'package:angular2/src/facade/exceptions.dart';
 
 class GenericMessageBus implements MessageBus {
-  MessageBusSink sink;
-  MessageBusSource source;
+  final MessageBusSink _sink;
+  final MessageBusSource _source;
+
+  MessageBusSink get sink => _sink;
+  MessageBusSource get source => _source;
 
   GenericMessageBus(MessageBusSink sink, MessageBusSource source)
-      : sink = sink,
-        source = source;
+      : _sink = sink,
+        _source = source;
 
   void attachToZone(NgZone zone) {
-    sink.attachToZone(zone);
-    source.attachToZone(zone);
+    _sink.attachToZone(zone);
+    _source.attachToZone(zone);
   }
 
   void initChannel(String channel, [bool runInZone = true]) {
-    sink.initChannel(channel, runInZone);
-    source.initChannel(channel, runInZone);
+    _sink.initChannel(channel, runInZone);
+    _source.initChannel(channel, runInZone);
   }
 
   EventEmitter from(String channel) {
-    return source.from(channel);
+    return _source.from(channel);
   }
 
   EventEmitter to(String channel) {
-    return sink.to(channel);
+    return _sink.to(channel);
   }
 }