Shows chrome-extension urls and greys out the whole url.

chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.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 "chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.h"
 
 #include <Carbon/Carbon.h>  // kVK_Return
 
 #include "base/mac/foundation_util.h"
 #include "base/string_util.h"
@@ skipping 437 matching lines @@
              range:as_entire_string];
 
   url_parse::Component scheme, host;
   AutocompleteInput::ParseForEmphasizeComponents(
       display_text, &scheme, &host);
   const bool emphasize = model()->CurrentTextIsURL() && (host.len > 0);
   if (emphasize) {
     [as addAttribute:NSForegroundColorAttributeName value:BaseTextColor()
                range:as_entire_string];
 
-    [as addAttribute:NSForegroundColorAttributeName value:HostTextColor()
+    if (!toolbar_model()->ShouldNotEmphasizeHost()) {
+      [as addAttribute:NSForegroundColorAttributeName value:HostTextColor()
                range:ComponentToNSRange(host)];
+    }
   }
 
   // TODO(shess): GTK has this as a member var, figure out why.
   // [Could it be to not change if no change?  If so, I'm guessing
   // AppKit may already handle that.]
   const ToolbarModel::SecurityLevel security_level =
       toolbar_model()->GetSecurityLevel();
 
   // Emphasize the scheme for security UI display purposes (if necessary).
   if (!model()->user_input_in_progress() && model()->CurrentTextIsURL() &&
@@ skipping 506 matching lines @@
 
 NSUInteger OmniboxViewMac::GetTextLength() const {
   return [field_ currentEditor] ?  [[[field_ currentEditor] string] length] :
                                    [[field_ stringValue] length];
 }
 
 bool OmniboxViewMac::IsCaretAtEnd() const {
   const NSRange selection = GetSelectedRange();
   return NSMaxRange(selection) == GetTextLength();
 }