Ensure strikethrough font renders in omnibox on iOS 10.3

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

 // 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.
 
 #include "ios/chrome/browser/ui/omnibox/omnibox_view_ios.h"
 
 #import <CoreText/CoreText.h>
 #import <MobileCoreServices/MobileCoreServices.h>
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/ios/device_util.h"
+#include "base/ios/ios_util.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/user_metrics.h"
 #include "base/metrics/user_metrics_action.h"
 #include "base/strings/string16.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/omnibox/browser/autocomplete_input.h"
 #include "components/omnibox/browser/autocomplete_match.h"
 #include "components/omnibox/browser/omnibox_edit_model.h"
 #include "components/omnibox/browser/omnibox_popup_model.h"
 #include "components/toolbar/toolbar_model.h"
@@ skipping 157 matching lines @@
       preloader_(preloader),
       ignore_popup_updates_(false),
       attributing_display_string_(nil) {
   popup_view_.reset(new OmniboxPopupViewIOS(this, model(), positioner));
   field_delegate_.reset(
       [[AutocompleteTextFieldDelegate alloc] initWithEditView:this]);
   [field_ setDelegate:field_delegate_];
   [field_ addTarget:field_delegate_
                 action:@selector(textFieldDidChange:)
       forControlEvents:UIControlEventEditingChanged];
+  use_strikethrough_workaround_ = base::ios::IsRunningOnOrLater(10, 3, 0);
 }
 
 OmniboxViewIOS::~OmniboxViewIOS() {
   // |field_| outlives this object.
   [field_ setDelegate:nil];
 
   [field_ removeTarget:field_delegate_
                 action:@selector(textFieldDidChange:)
       forControlEvents:UIControlEventEditingChanged];
 
@@ skipping 464 matching lines @@
 
   if ((security_level == security_state::NONE) ||
       (security_level == security_state::HTTP_SHOW_WARNING)) {
     return;
   }
 
   DCHECK_NE(security_state::SECURITY_WARNING, security_level);
   DCHECK_NE(security_state::SECURE_WITH_POLICY_INSTALLED_CERT, security_level);
 
   if (security_level == security_state::DANGEROUS) {
+    if (use_strikethrough_workaround_) {
+      // Workaround: Add extra attribute to allow strikethough to apply on iOS
+      // 10.3+. See https://crbug.com/699702 for discussion.
+      [attributing_display_string_
+          addAttribute:NSBaselineOffsetAttributeName
+                 value:@0
+                 range:NSMakeRange(0, [attributing_display_string_ length])];
+    }
+
     // Add a strikethrough through the scheme.
     [attributing_display_string_
         addAttribute:NSStrikethroughStyleAttributeName
                value:[NSNumber numberWithInteger:NSUnderlineStyleSingle]
                range:range.ToNSRange()];
   }
 
   UIColor* color = GetSecureTextColor(security_level, [field_ incognito]);
   if (color) {
     [attributing_display_string_ addAttribute:NSForegroundColorAttributeName
@@ skipping 189 matching lines @@
 // is being left out for now because it was not present before the OmniboxView
 // rewrite.
 #if 0
   // When editing is in progress, the url text is not colored, so there is
   // nothing to emphasize.  (Calling SetText() in that situation would also be
   // harmful, as it would reset the carat position to the end of the text.)
   if (!IsEditingOrEmpty())
     SetText(GetText());
 #endif
 }