[ios] Remove -topPresentedViewController from -showSigin

Bug: 
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I55e2b28607b850671d979b9542ca116dd266479e
Reviewed-on: https://chromium-review.googlesource.com/753933
Commit-Queue: edchin <[email protected]>
Reviewed-by: Mark Cogan <[email protected]>
Reviewed-by: edchin <[email protected]>
Cr-Commit-Position: refs/heads/master@{#514634}
diff --git a/ios/chrome/browser/ui/browser_view_controller.mm b/ios/chrome/browser/ui/browser_view_controller.mm
index abc5fb9..a502c5e 100644
--- a/ios/chrome/browser/ui/browser_view_controller.mm
+++ b/ios/chrome/browser/ui/browser_view_controller.mm
@@ -5386,10 +5386,12 @@
 
 - (void)showReauthenticateSignin {
   [self.dispatcher
-      showSignin:[[ShowSigninCommand alloc]
-                     initWithOperation:AUTHENTICATION_OPERATION_REAUTHENTICATE
-                           accessPoint:signin_metrics::AccessPoint::
-                                           ACCESS_POINT_UNKNOWN]];
+              showSignin:
+                  [[ShowSigninCommand alloc]
+                      initWithOperation:AUTHENTICATION_OPERATION_REAUTHENTICATE
+                            accessPoint:signin_metrics::AccessPoint::
+                                            ACCESS_POINT_UNKNOWN]
+      baseViewController:self];
 }
 
 - (void)showSyncSettings {
@@ -5403,7 +5405,7 @@
 #pragma mark - SigninPresenter
 
 - (void)showSignin:(ShowSigninCommand*)command {
-  [self.dispatcher showSignin:command];
+  [self.dispatcher showSignin:command baseViewController:self];
 }
 
 @end