Remove workaround for strikethrough text in iOS omnibox

ios/chrome/browser/ui/omnibox/omnibox_view_ios.h

 // Copyright (c) 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.
 
 #ifndef IOS_CHROME_BROWSER_UI_OMNIBOX_OMNIBOX_VIEW_IOS_H_
 #define IOS_CHROME_BROWSER_UI_OMNIBOX_OMNIBOX_VIEW_IOS_H_
 
 #import <UIKit/UIKit.h>
 
 #include <memory>
@@ skipping 158 matching lines @@
   base::scoped_nsobject<NSString> marked_text_before_change_;
   NSRange current_selection_;
   NSRange old_selection_;
 
   // TODO(rohitrao): This is a monster hack, needed because closing the popup
   // ends up inadvertently triggering a new round of autocomplete.  Fix the
   // underlying problem, which is that textDidChange: is called when closing the
   // popup, and then remove this hack.  b/5877366.
   BOOL ignore_popup_updates_;
 
-  // iOS 10.3 fails to apply the strikethrough style unless an extra style is
-  // also applied. See https://crbug.com/699702 for discussion.
-  BOOL use_strikethrough_workaround_;
-
   // Bridges delegate method calls from |field_| to C++ land.
   base::scoped_nsobject<AutocompleteTextFieldDelegate> field_delegate_;
 
   // Temporary pointer to the attributed display string, stored as color and
   // other emphasis attributes are applied by the superclass.
   NSMutableAttributedString* attributing_display_string_;  // weak
 };
 
 #endif  // IOS_CHROME_BROWSER_UI_OMNIBOX_OMNIBOX_VIEW_IOS_H_