Revert "Remove workaround for strikethrough text in iOS omnibox"

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

Index: ios/chrome/browser/ui/omnibox/omnibox_view_ios.mm
diff --git a/ios/chrome/browser/ui/omnibox/omnibox_view_ios.mm b/ios/chrome/browser/ui/omnibox/omnibox_view_ios.mm
index 3114bc7d51ee53811d96b7f5deaf647125d13a75..1eabef3394dda9f245f33bf0ed7a9b5d2db7cbca 100644
--- a/ios/chrome/browser/ui/omnibox/omnibox_view_ios.mm
+++ b/ios/chrome/browser/ui/omnibox/omnibox_view_ios.mm
@@ -10,6 +10,7 @@
 #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"
@@ -180,6 +181,7 @@ OmniboxViewIOS::OmniboxViewIOS(OmniboxTextFieldIOS* field,
   [field_ addTarget:field_delegate_
                 action:@selector(textFieldDidChange:)
       forControlEvents:UIControlEventEditingChanged];
+  use_strikethrough_workaround_ = base::ios::IsRunningOnOrLater(10, 3, 0);
 }
 
 OmniboxViewIOS::~OmniboxViewIOS() {
@@ -646,6 +648,15 @@ void OmniboxViewIOS::UpdateSchemeStyle(const gfx::Range& range) {
   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