Revert of Removes usage of signin APIs that return scoped_nsobjects.

ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.mm

Index: ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.mm
diff --git a/ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.mm b/ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.mm
index e1d8a7160e075fa9576fd84a1b7138967aa40c0a..d68a3397bdcfeefb187ce72836dc081b86ce877e 100644
--- a/ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.mm
+++ b/ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.mm
@@ -142,8 +142,8 @@
       ios::GetChromeBrowserProvider()->GetChromeIdentityService());
 }
 
-UINavigationController*
-FakeChromeIdentityService::CreateAccountDetailsController(
+base::scoped_nsobject<UINavigationController>
+FakeChromeIdentityService::NewAccountDetails(
     ChromeIdentity* identity,
     id<ChromeIdentityBrowserOpener> browser_opener) {
   base::scoped_nsobject<UIViewController> accountDetailsViewController(
@@ -154,13 +154,13 @@
   return navigationController;
 }
 
-ChromeIdentityInteractionManager*
-FakeChromeIdentityService::CreateChromeIdentityInteractionManager(
+base::scoped_nsobject<ChromeIdentityInteractionManager>
+FakeChromeIdentityService::NewChromeIdentityInteractionManager(
     ios::ChromeBrowserState* browser_state,
     id<ChromeIdentityInteractionManagerDelegate> delegate) const {
-  ChromeIdentityInteractionManager* manager =
-      [[[FakeChromeIdentityInteractionManager alloc] init] autorelease];
-  manager.delegate = delegate;
+  base::scoped_nsobject<ChromeIdentityInteractionManager> manager(
+      [[FakeChromeIdentityInteractionManager alloc] init]);
+  manager.get().delegate = delegate;
   return manager;
 }