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

chrome/browser/ui/toolbar/toolbar_model_impl.cc

 // Copyright 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/toolbar/toolbar_model_impl.h"
 
 #include "base/command_line.h"
 #include "base/prefs/pref_service.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/autocomplete/autocomplete_classifier.h"
@@ skipping 161 matching lines @@
   if (entry && entry->GetURL().SchemeIs(chrome::kDriveScheme))
     return false;
 #endif
 
   if (chrome::IsInstantNTP(web_contents))
     return false;
 
   return true;
 }
 
+bool ToolbarModelImpl::ShouldGreyOutURL() const {
+  WebContents* web_contents = delegate_->GetActiveWebContents();
+  if (web_contents && web_contents->GetWebUIForCurrentState())

[sky, 2013/04/03 04:03:57]

nit: make this a single return, eg:
return web_contents && web_contents->.. && web_contents()->GetWe...

+    return web_contents->GetWebUIForCurrentState()->ShouldGreyOutURL();
+  return false;
+}
+
 ToolbarModel::SecurityLevel ToolbarModelImpl::GetSecurityLevel() const {
   if (input_in_progress_)  // When editing, assume no security style.
     return NONE;
 
   return GetSecurityLevelForWebContents(delegate_->GetActiveWebContents());
 }
 
 int ToolbarModelImpl::GetIcon() const {
   if (WouldReplaceSearchURLWithSearchTerms())
     return IDR_OMNIBOX_SEARCH;
@@ skipping 69 matching lines @@
     Profile* profile =
         Profile::FromBrowserContext(contents->GetBrowserContext());
     AutocompleteClassifierFactory::GetForProfile(profile)->Classify(
         search_terms, false, false, &match, NULL);
     if (!AutocompleteMatch::IsSearchType(match.type))
       search_terms.clear();
   }
 
   return search_terms;
 }