Cancels payment request when Settings is tapped, and opens the Autofill settings page.

ios/chrome/app/main_controller.mm

Index: ios/chrome/app/main_controller.mm
diff --git a/ios/chrome/app/main_controller.mm b/ios/chrome/app/main_controller.mm
index 8a79c1c182460c740091136e3cb954c7ae19fb91..25c25d81a5e68f0154c9c3d02a013151cf9ed176 100644
--- a/ios/chrome/app/main_controller.mm
+++ b/ios/chrome/app/main_controller.mm
@@ -1521,6 +1521,9 @@ enum class StackViewDismissalMode { NONE, NORMAL, INCOGNITO };
     case IDC_SHOW_ADD_ACCOUNT:
       [self showAddAccount];
       break;
+    case IDC_SHOW_AUTOFILL_SETTINGS:
+      [self showAutofillSettings];
+      break;
     default:
       // Unknown commands get dropped with a warning.
       NOTREACHED() << "Unknown command id " << command;
@@ -2013,6 +2016,18 @@ enum class StackViewDismissalMode { NONE, NORMAL, INCOGNITO };
                  completion:nil];
 }
 
+- (void)showAutofillSettings {
+  if (_settingsNavigationController)
+    return;
+  _settingsNavigationController.reset([SettingsNavigationController
+      newAutofillController:_mainBrowserState
+                   delegate:self]);
+  [[self topPresentedViewController]
+      presentViewController:_settingsNavigationController
+                   animated:YES
+                 completion:nil];
+}
+
 - (void)showReportAnIssue {
   if (_settingsNavigationController)
     return;