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

ios/chrome/browser/ui/browser_view_controller.mm

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/chrome/browser/ui/browser_view_controller.h"
 
 #import <AssetsLibrary/AssetsLibrary.h>
 #import <MobileCoreServices/MobileCoreServices.h>
 #import <PassKit/PassKit.h>
 #import <Photos/Photos.h>
@@ skipping 3399 matching lines @@
   // conditions. However a crash was seen were navItem was NULL hence this
   // test after a DCHECK.
   DCHECK(navItem);
   if (!navItem)
     return;
 
   // Don't show if the page is native.
   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).
   [_toolbarController cancelOmniboxEdit];
 
   [[NSNotificationCenter defaultCenter]
       postNotificationName:ios_internal::kPageInfoWillShowNotification
                     object:nil];
 
   // TODO(rohitrao): Get rid of PageInfoModel completely.
@@ skipping 1739 matching lines @@
 
 - (UIView*)voiceSearchButton {
   return _voiceSearchButton;
 }
 
 - (id<LogoAnimationControllerOwner>)logoAnimationControllerOwner {
   return [self currentLogoAnimationControllerOwner];
 }
 
 @end