[ios] Prevent multiple page security popups in voice over mode.

ios/chrome/browser/ui/browser_view_controller.mm

Index: ios/chrome/browser/ui/browser_view_controller.mm
diff --git a/ios/chrome/browser/ui/browser_view_controller.mm b/ios/chrome/browser/ui/browser_view_controller.mm
index f6623048705ccd76ded971a33c1cfbb103683fdb..591c27a3994fb1075513de44fddad4a635aab345 100644
--- a/ios/chrome/browser/ui/browser_view_controller.mm
+++ b/ios/chrome/browser/ui/browser_view_controller.mm
@@ -3417,6 +3417,11 @@ class BrowserBookmarkModelBridge : public bookmarks::BookmarkModelObserver {
   if ([self isTabNativePage:tab])
     return;
 
+  // Don't show the bubble twice (this can happen when tapping very quickly in
+  // accessibility mode).
+  if (_pageInfoController)
+    return;
+
   base::RecordAction(UserMetricsAction("MobileToolbarPageSecurityInfo"));
 
   // Dismiss the omnibox (if open).