Don't dismiss Settings when another view controller is presented on top

ios/public/provider/chrome/browser/signin/fake_chrome_identity_interaction_manager.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/public/provider/chrome/browser/signin/fake_chrome_identity_interaction_manager.h"
 
 #include "base/mac/scoped_block.h"
 #include "base/mac/scoped_nsobject.h"
 #import "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 #import "ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.h"
@@ skipping 47 matching lines @@
 
   _signInButton.reset([[UIButton buttonWithType:UIButtonTypeCustom] retain]);
   [_signInButton setTitle:@"Sign in" forState:UIControlStateNormal];
   [_signInButton addTarget:self
                     action:@selector(didTapSignIn:)
           forControlEvents:UIControlEventTouchUpInside];
   [self.view addSubview:_signInButton];
 
   _cancelButton.reset([[UIButton buttonWithType:UIButtonTypeCustom] retain]);
   [_cancelButton setTitle:@"Cancel" forState:UIControlStateNormal];
+  [_cancelButton setAccessibilityIdentifier:@"cancel"];
   [_cancelButton addTarget:self
                     action:@selector(didTapCancel:)
           forControlEvents:UIControlEventTouchUpInside];
   [self.view addSubview:_cancelButton];
 }
 
 - (void)viewWillLayoutSubviews {
   [super viewWillLayoutSubviews];
 
   CGRect bounds = self.view.bounds;
@@ skipping 85 matching lines @@
 
 - (NSError*)canceledError {
   ios::SigninErrorProvider* provider =
       ios::GetChromeBrowserProvider()->GetSigninErrorProvider();
   return [NSError errorWithDomain:provider->GetSigninErrorDomain()
                              code:provider->GetCode(ios::SigninError::CANCELED)
                          userInfo:nil];
 }
 
 @end