docs(*): Document a lot more symbols that are missing comments in our generated docs.

modules/angular2/src/platform/browser/browser_adapter.ts

@@ -53,6 +53,9 @@ var _chromeNumKeyPadMap = {
   '\x90': 'NumLock'
 };
 
+/**
+ * A `DomAdapter` powered by full browser DOM APIs.
+ */
 /* tslint:disable:requireParameterType */
 export class BrowserDomAdapter extends GenericBrowserDomAdapter {
   parse(templateHtml: string) { throw new Error("parse not implemented"); }