chore(typescript): fixes dart failures and linter

Closes #4359

modules/angular2/src/core/render/dom/compiler/style_inliner.ts

@@ -91,7 +91,7 @@ export class StyleInliner {
     }
 
     return PromiseWrapper.all(promises).then(function(cssParts) {
-      var cssText = cssParts.join('');
+      var cssText = (<any[]>cssParts).join('');
       if (partIndex < parts.length) {
         // append then content located after the last @import rule
         cssText += parts[partIndex];

modules/angular2/src/core/render/dom/view/shared_styles_host.ts

@@ -5,8 +5,8 @@ import {DOCUMENT} from '../dom_tokens';
 
 @Injectable()
 export class SharedStylesHost {
-  protected _styles: string[] = [];
-  protected _stylesSet: Set<string> = new Set();
+  _styles: string[] = [];
+  _stylesSet: Set<string> = new Set();
 
   constructor() {}
 
@@ -22,7 +22,7 @@ export class SharedStylesHost {
     this.onStylesAdded(additions);
   }
 
-  protected onStylesAdded(additions: string[]) {}
+  onStylesAdded(additions: string[]) {}
 
   getAllStyles(): string[] { return this._styles; }
 }