Revert "Remove workaround for strikethrough text in iOS omnibox"

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

Index: ios/chrome/browser/ui/omnibox/omnibox_view_ios.h
diff --git a/ios/chrome/browser/ui/omnibox/omnibox_view_ios.h b/ios/chrome/browser/ui/omnibox/omnibox_view_ios.h
index 8e75d6620324dd4472c79284f20f0e2a732d9bf4..469b1afe9da8822af8496af71102b4a7c7114202 100644
--- a/ios/chrome/browser/ui/omnibox/omnibox_view_ios.h
+++ b/ios/chrome/browser/ui/omnibox/omnibox_view_ios.h
@@ -174,6 +174,10 @@ class OmniboxViewIOS : public OmniboxView {
   // 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_;