[Mac] Misc fixes for the new avatar bubble

chrome/browser/ui/cocoa/website_settings/website_settings_bubble_controller.mm

Index: chrome/browser/ui/cocoa/website_settings/website_settings_bubble_controller.mm
diff --git a/chrome/browser/ui/cocoa/website_settings/website_settings_bubble_controller.mm b/chrome/browser/ui/cocoa/website_settings/website_settings_bubble_controller.mm
index efb737a5fc66937f6bf98696feb10968778d8fee..450e2f8267254ccb434154240d7ab692ead4a44a 100644
--- a/chrome/browser/ui/cocoa/website_settings/website_settings_bubble_controller.mm
+++ b/chrome/browser/ui/cocoa/website_settings/website_settings_bubble_controller.mm
@@ -808,8 +808,8 @@ NSColor* IdentityVerifiedTextColor() {
   CGFloat width = NSWidth([view frame]) - 2 * kFramePadding;
 
   // Use an arbitrary position; it will be adjusted in performLayout.
-  NSBox* spacer =
-      [self separatorWithFrame:NSMakeRect(kFramePadding, 0, width, 0)];
+  NSBox* spacer = [self horizontalSeparatorWithFrame:NSMakeRect(
+      kFramePadding, 0, width, 0)];
   [view addSubview:spacer];
   return spacer;
 }