Present the advanced sign-in settings from SigninPromoViewController.

This CL adds a temporary solution to present the advanced sign-in
settings when the user taps on settings on the sign-in promo screen.

This is a temporary solution as the plan is to move the ownership of
the SigninPromoViewController to the SigninInteractionCoordinator
(see crbug.com/965992). However it is preferred to only make this change
after the unified consent feature is launched as it is fairly complex to
do if we want to also support pre-unified consent flows.

Bug: 963412

Change-Id: Iee3216254e2b42dbaed39503af58851980a7c9bb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1625110
Commit-Queue: Mihai Sardarescu <msarda@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Reviewed-by: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662647}

ios/chrome/browser/ui/promos/BUILD.gn

@@ -12,6 +12,7 @@ source_set("promos") {
   deps = [
     "//base",
     "//components/signin/core/browser",
+    "//components/unified_consent",
     "//components/version_info",
     "//ios/chrome/app:tests_hook",
     "//ios/chrome/app/strings",

ios/chrome/browser/ui/promos/signin_promo_view_controller.mm

@@ -9,6 +9,7 @@
 #include "base/strings/sys_string_conversions.h"
 #include "base/version.h"
 #include "components/signin/core/browser/signin_metrics.h"
+#include "components/unified_consent/feature.h"
 #include "components/version_info/version_info.h"
 #include "ios/chrome/app/tests_hook.h"
 #import "ios/chrome/browser/browser_state/chrome_browser_state.h"
@@ -110,18 +111,23 @@ NSSet* GaiaIdSetWithIdentities(NSArray* identities) {
 - (void)dismissWithSignedIn:(BOOL)signedIn
        showAccountsSettings:(BOOL)showAccountsSettings {
   DCHECK(self.presentingViewController);
+  ProceduralBlock completion = nil;
+  if (showAccountsSettings) {
     __weak UIViewController* presentingViewController =
         self.presentingViewController;
-  __weak id<ApplicationCommands> weakDispatcher = self.dispatcher;
-  [presentingViewController
-      dismissViewControllerAnimated:YES
-                         completion:^{
-                           if (showAccountsSettings) {
-                             [weakDispatcher
-                                 showAccountsSettingsFromViewController:
+    __weak id<ApplicationCommands> dispatcher = self.dispatcher;
+    completion = ^{
+      if (unified_consent::IsUnifiedConsentFeatureEnabled()) {
+        [dispatcher showAdvancedSigninSettingsFromViewController:
                         presentingViewController];
+      } else {
+        [dispatcher
+            showAccountsSettingsFromViewController:presentingViewController];
+      }
+    };
   }
-                         }];
+  [self.presentingViewController dismissViewControllerAnimated:YES
+                                                    completion:completion];
 }
 
 // Records in user defaults that the promo has been shown as well as the number