Enabled pressing TAB to cycle through the Omnibox results.

chrome/browser/autocomplete/keyword_provider.cc

 // Copyright (c) 2011 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/autocomplete/keyword_provider.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/string16.h"
@@ skipping 161 matching lines @@
   // don't bother.
   //
   // TODO(pkasting): http://b/893701 We should remember the user's use of a
   // search query both from the autocomplete popup and from web pages
   // themselves.
   std::vector<string16> keyword_matches;
   model->FindMatchingKeywords(keyword,
                               !remaining_input.empty(),
                               &keyword_matches);
 
-  // Prune any extension keywords that are disallowed in incognito mode (if
-  // we're incognito), or disabled.
   for (std::vector<string16>::iterator i(keyword_matches.begin());
        i != keyword_matches.end(); ) {
     const TemplateURL* template_url(model->GetTemplateURLForKeyword(*i));
+
+    // Prune any extension keywords that are disallowed in incognito mode (if
+    // we're incognito), or disabled.
     if (profile_ &&
         input.matches_requested() == AutocompleteInput::ALL_MATCHES &&
         template_url->IsExtensionKeyword()) {
       ExtensionService* service = profile_->GetExtensionService();
       const Extension* extension = service->GetExtensionById(
           template_url->GetExtensionId(), false);
       bool enabled =
           extension && (!profile_->IsOffTheRecord() ||
                         service->IsIncognitoEnabled(extension->id()));
       if (!enabled) {
         i = keyword_matches.erase(i);
         continue;
       }
     }
+
+    // Prune any substituting keywords if there is no substitution.
+    if (TemplateURL::SupportsReplacement(template_url) &&
+        !input.allow_exact_keyword_match()) {
+      i = keyword_matches.erase(i);
+      continue;
+    }
     ++i;
   }
   if (keyword_matches.empty())
     return;
   std::sort(keyword_matches.begin(), keyword_matches.end(), CompareQuality());
 
   // Limit to one exact or three inexact matches, and mark them up for display
   // in the autocomplete popup.
   // Any exact match is going to be the highest quality match, and thus at the
   // front of our vector.
@@ skipping 322 matching lines @@
 }
 
 void KeywordProvider::MaybeEndExtensionKeywordMode() {
   if (!current_keyword_extension_id_.empty()) {
     ExtensionOmniboxEventRouter::OnInputCancelled(
         profile_, current_keyword_extension_id_);
 
     current_keyword_extension_id_.clear();
   }
 }