[CRD iOS] Add the host setup instruction page

remoting/ios/app/app_delegate.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.
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 #import "remoting/ios/app/app_delegate.h"
 
@@ skipping 129 matching lines @@
   NSURLRequest* request =
       [NSURLRequest requestWithURL:[NSURL URLWithString:url]];
   WKWebView* webView =
       [[WKWebView alloc] initWithFrame:viewController.view.frame
                          configuration:[[WKWebViewConfiguration alloc] init]];
   [viewController.view addSubview:webView];
   [navigationController pushViewController:viewController animated:YES];
   [webView loadRequest:request];
 }
 
+- (void)emailSetupInstructions {
+  NSLog(@"TODO: emailSetupInstructions");
+}
+
 @end