refactor(ElementBinderBuilder): remove unused code

Closes angular#3326

Author: pkozlowski-opensource

modules/angular2/src/render/dom/view/proto_view_builder.ts

@@ -149,7 +149,6 @@ export class ElementBinderBuilder {
  nestedProtoView: ProtoViewBuilder = null;
  propertyBindings: Map<string, ASTWithSource> = new Map();
  variableBindings: Map<string, string> = new Map();
- propertyBindingsToDirectives: Set<string> = new Set();
  eventBindings: List<api.EventBinding> = [];
  eventBuilder: EventBuilder = new EventBuilder();
  textBindings: Map<Node, ASTWithSource> = new Map();
@@ -191,12 +190,6 @@ export class ElementBinderBuilder {
  this.propertyBindings.set(name, expression);
  }
 
- bindPropertyToDirective(name: string) {
- // we are filling in a set of property names that are bound to a property
- // of at least one directive. This allows us to report "dangling" bindings.
- this.propertyBindingsToDirectives.add(name);
- }
-
  bindVariable(name: string, value: string) {
  // When current is a view root, the variable bindings are set to the *nested* proto view.
  // The root view conceptually signifies a new "block scope" (the nested view), to which