[ObjC ARC] Converts ios/chrome/browser/signin:test_support to ARC.

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"
 #include "ios/public/provider/chrome/browser/signin/signin_error_provider.h"
 
 @interface FakeAddAccountViewController : UIViewController {
   FakeChromeIdentityInteractionManager* _manager;  // Weak.
-  base::scoped_nsobject<UIButton> _cancelButton;
-  base::scoped_nsobject<UIButton> _signInButton;
+  UIButton* _cancelButton;
+  UIButton* _signInButton;
 }
 @end
 
 @interface FakeChromeIdentityInteractionManager () {
-  base::mac::ScopedBlock<SigninCompletionCallback> _completionCallback;
-  base::scoped_nsobject<UIViewController> _viewController;
+  SigninCompletionCallback _completionCallback;
+  UIViewController* _viewController;
   BOOL _isCanceling;
 }
 
 - (void)addAccountViewControllerDidTapSignIn:(FakeAddAccountViewController*)vc;
 
 - (void)addAccountViewControllerDidTapCancel:(FakeAddAccountViewController*)vc;
 
 @end
 
 @implementation FakeAddAccountViewController
@@ skipping 16 matching lines @@
              forControlEvents:UIControlEventTouchUpInside];
   [super dealloc];
 }
 
 - (void)viewDidLoad {
   [super viewDidLoad];
 
   // Obnoxious color, this is a test screen.
   self.view.backgroundColor = [UIColor magentaColor];
 
-  _signInButton.reset([[UIButton buttonWithType:UIButtonTypeCustom] retain]);
+  _signInButton = [[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 = [[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];
@@ skipping 19 matching lines @@
 
 @implementation FakeChromeIdentityInteractionManager
 
 @synthesize fakeIdentity = _fakeIdentity;
 
 - (BOOL)isCanceling {
   return _isCanceling;
 }
 
 - (void)addAccountWithCompletion:(SigninCompletionCallback)completion {
-  _completionCallback.reset(completion, base::scoped_policy::RETAIN);
-  _viewController.reset(
-      [[FakeAddAccountViewController alloc] initWithInteractionManager:self]);
+  _completionCallback = [completion copy];
+  _viewController =
+      [[FakeAddAccountViewController alloc] initWithInteractionManager:self];
   [self.delegate interactionManager:self
               presentViewController:_viewController
                            animated:YES
                          completion:nil];
 }
 
 - (void)reauthenticateUserWithID:(NSString*)userID
                            email:(NSString*)userEmail
                       completion:(SigninCompletionCallback)completion {
   [self addAccountWithCompletion:completion];
@@ skipping 26 matching lines @@
     return;
   }
   [self.delegate interactionManager:self
       dismissViewControllerAnimated:animated
                          completion:^{
                            [self runCompletionCallbackWithError:error];
                          }];
 }
 
 - (void)runCompletionCallbackWithError:(NSError*)error {
-  _viewController.reset();
+  _viewController = nil;
   if (_completionCallback) {
     // Ensure self is not destroyed in the callback.
-    base::scoped_nsobject<FakeChromeIdentityInteractionManager> strongSelf(
-        [self retain]);
-    _completionCallback.get()(error ? nil : _fakeIdentity, error);
-    _completionCallback.reset();
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-variable"
+    FakeChromeIdentityInteractionManager* strongSelf = self;
+#pragma clang diagnostic pop
+    _completionCallback(error ? nil : _fakeIdentity, error);
+    _completionCallback = nil;
   }
 }
 
 - (NSError*)canceledError {
   ios::SigninErrorProvider* provider =
       ios::GetChromeBrowserProvider()->GetSigninErrorProvider();
   return [NSError errorWithDomain:provider->GetSigninErrorDomain()
                              code:provider->GetCode(ios::SigninError::CANCELED)
                          userInfo:nil];
 }
 
 @end