Adds signin provider APIs that don't return scoped_nsobjects.

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

Index: ios/public/provider/chrome/browser/signin/chrome_identity_service.mm
diff --git a/ios/public/provider/chrome/browser/signin/chrome_identity_service.mm b/ios/public/provider/chrome/browser/signin/chrome_identity_service.mm
index e19e1eee4c25a73442f3d8f918f4a9fc412b5ec4..05cbbbd7d8ff9d980f0189f9152eb58cf42ca998 100644
--- a/ios/public/provider/chrome/browser/signin/chrome_identity_service.mm
+++ b/ios/public/provider/chrome/browser/signin/chrome_identity_service.mm
@@ -23,6 +23,26 @@ bool ChromeIdentityService::HandleApplicationOpenURL(UIApplication* application,
   return false;
 }
 
+UINavigationController* ChromeIdentityService::CreateAccountDetailsController(
+    ChromeIdentity* identity,
+    id<ChromeIdentityBrowserOpener> browser_opener) {
+  return nil;
+}
+
+UINavigationController*
+ChromeIdentityService::CreateWebAndAppSettingDetailsController(
+    ChromeIdentity* identity,
+    id<ChromeIdentityBrowserOpener> browser_opener) {
+  return nil;
+}
+
+ChromeIdentityInteractionManager*
+ChromeIdentityService::CreateChromeIdentityInteractionManager(
+    ios::ChromeBrowserState* browser_state,
+    id<ChromeIdentityInteractionManagerDelegate> delegate) const {
+  return nil;
+}
+
 base::scoped_nsobject<UINavigationController>
 ChromeIdentityService::NewAccountDetails(
     ChromeIdentity* identity,