Update web shell app to not load dev.chromium.org on launch.

ios/web/shell/test/earl_grey/shell_base_test_case.mm

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/web/shell/test/earl_grey/shell_base_test_case.h"
 
 #import <EarlGrey/EarlGrey.h>
 
 #import "ios/web/public/test/http_server.h"
 #import "ios/web/shell/test/earl_grey/shell_matchers.h"
@@ skipping 21 matching lines @@
   if (error != nil) {
     NSLog(@"System alert view is present, so skipping all tests!");
     return @[];
   }
   return [super testInvocations];
 }
 
 // Set up called once for the class.
 + (void)setUp {
   [super setUp];
-  [[EarlGrey selectElementWithMatcher:WebViewContainingText("Chromium")]
-      assertWithMatcher:grey_notNil()];
   HttpServer::GetSharedInstance().StartOrDie();
 }
 
 // Tear down called once for the class.
 + (void)tearDown {
   HttpServer::GetSharedInstance().Stop();
   [super tearDown];
 }
 
 // Tear down called after each test.
 - (void)tearDown {
   HttpServer::GetSharedInstance().RemoveAllResponseProviders();
   [super tearDown];
 }
 
 @end