refactor(StringWrapper): remove useless methods

Closes #5039

modules/angular2/src/router/path_recognizer.ts

@@ -93,8 +93,8 @@ var wildcardMatcher = /^\*([^\/]+)$/g;
 function parsePathString(route: string): {[key: string]: any} {
   // normalize route as not starting with a "/". Recognition will
   // also normalize.
-  if (StringWrapper.startsWith(route, "/")) {
-    route = StringWrapper.substring(route, 1);
+  if (route.startsWith("/")) {
+    route = route.substring(1);
   }
 
   var segments = splitBySlash(route);

modules/angular2/src/router/route_recognizer.ts

@@ -1,7 +1,6 @@
 import {
   RegExp,
   RegExpWrapper,
-  StringWrapper,
   isBlank,
   isPresent,
   isType,
@@ -46,8 +45,7 @@ export class RouteRecognizer {
 
     if (config instanceof AuxRoute) {
       handler = new SyncRouteHandler(config.component, config.data);
-      let path =
-          StringWrapper.startsWith(config.path, '/') ? config.path.substring(1) : config.path;
+      let path = config.path.startsWith('/') ? config.path.substring(1) : config.path;
       var recognizer = new PathRecognizer(config.path, handler);
       this.auxRoutes.set(path, recognizer);
       return recognizer.terminal;
@@ -136,11 +134,11 @@ export class Redirector {
   toSegments: string[] = [];
 
   constructor(path: string, redirectTo: string) {
-    if (StringWrapper.startsWith(path, '/')) {
+    if (path.startsWith('/')) {
       path = path.substring(1);
     }
     this.segments = path.split('/');
-    if (StringWrapper.startsWith(redirectTo, '/')) {
+    if (redirectTo.startsWith('/')) {
       redirectTo = redirectTo.substring(1);
     }
     this.toSegments = redirectTo.split('/');

modules/angular2/src/router/router.ts

@@ -5,14 +5,7 @@ import {
   ObservableWrapper
 } from 'angular2/src/core/facade/async';
 import {Map, StringMapWrapper, MapWrapper, ListWrapper} from 'angular2/src/core/facade/collection';
-import {
-  isBlank,
-  isString,
-  StringWrapper,
-  isPresent,
-  Type,
-  isArray
-} from 'angular2/src/core/facade/lang';
+import {isBlank, isString, isPresent, Type, isArray} from 'angular2/src/core/facade/lang';
 import {BaseException, WrappedException} from 'angular2/src/core/facade/exceptions';
 import {RouteRegistry} from './route_registry';
 import {
@@ -537,11 +530,11 @@ class ChildRouter extends Router {
  * Given: ['/a/b', {c: 2}]
  * Returns: ['', 'a', 'b', {c: 2}]
  */
-var SLASH = new RegExp('/');
 function splitAndFlattenLinkParams(linkParams: any[]): any[] {
   return ListWrapper.reduce(linkParams, (accumulation, item) => {
     if (isString(item)) {
-      return accumulation.concat(StringWrapper.split(item, SLASH));
+      let parts: String[] = item.split('/');
+      return accumulation.concat(parts);
     }
     accumulation.push(item);
     return accumulation;

modules/angular2/src/router/url_parser.ts

@@ -1,11 +1,5 @@
 import {StringMapWrapper} from 'angular2/src/core/facade/collection';
-import {
-  isPresent,
-  isBlank,
-  StringWrapper,
-  RegExpWrapper,
-  CONST_EXPR
-} from 'angular2/src/core/facade/lang';
+import {isPresent, isBlank, RegExpWrapper, CONST_EXPR} from 'angular2/src/core/facade/lang';
 import {BaseException, WrappedException} from 'angular2/src/core/facade/exceptions';
 
 /**
@@ -79,10 +73,10 @@ function matchUrlSegment(str: string): string {
 export class UrlParser {
   private _remaining: string;
 
-  peekStartsWith(str: string): boolean { return StringWrapper.startsWith(this._remaining, str); }
+  peekStartsWith(str: string): boolean { return this._remaining.startsWith(str); }
 
   capture(str: string): void {
-    if (!StringWrapper.startsWith(this._remaining, str)) {
+    if (!this._remaining.startsWith(str)) {
       throw new BaseException(`Expected "${str}".`);
     }
     this._remaining = this._remaining.substring(str.length);