Remove secure icon todo

The behavior that is expected is the current behavior. Remove todo.

Bug: 848732
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ifc0412d8b0cca13e1b1342195608c7daecdbd46c
Reviewed-on: https://chromium-review.googlesource.com/1125733Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: Elodie Banel <lod@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572582}

ios/chrome/browser/ui/omnibox/omnibox_util.cc

@@ -122,9 +122,7 @@ base::string16 GetUIRefreshIconNameForSecurityState(
       return base::ASCIIToUTF16("location_bar_insecure");
     case security_state::EV_SECURE:
     case security_state::SECURE:
-      return base::ASCIIToUTF16("location_bar_secure");
     case security_state::SECURE_WITH_POLICY_INSTALLED_CERT:
-      // TODO(crbug.com/848732): update this icon.
       return base::ASCIIToUTF16("location_bar_secure");
     case security_state::DANGEROUS:
       return base::ASCIIToUTF16("location_bar_dangerous");