alternate ntp: persist show-search-provider-logo option at chrome://instant

chrome/browser/autocomplete/zero_suggest_provider.cc

 // 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/autocomplete/zero_suggest_provider.h"
 
 #include "base/callback.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/string16.h"
 #include "base/string_util.h"
@@ skipping 35 matching lines @@
 ZeroSuggestProvider::ZeroSuggestProvider(
   AutocompleteProviderListener* listener,
   Profile* profile,
   const std::string& url_prefix)
     : AutocompleteProvider(listener, profile,
           AutocompleteProvider::TYPE_ZERO_SUGGEST),
       url_prefix_(url_prefix),
       template_url_service_(TemplateURLServiceFactory::GetForProfile(profile)) {
 }
 
-// static
-void ZeroSuggestProvider::RegisterUserPrefs(PrefService* user_prefs) {
-  user_prefs->RegisterStringPref(prefs::kExperimentalZeroSuggestUrlPrefix, "",
-                                 PrefService::UNSYNCABLE_PREF);
-}
-
 void ZeroSuggestProvider::Start(const AutocompleteInput& input,
                                 bool /*minimal_changes*/) {
   UpdateMatches(input.text());
 }
 
 void ZeroSuggestProvider::StartZeroSuggest(const GURL& url,
                                            const string16& user_text) {
   DCHECK(url.is_valid());
   // Do not query non-http URLs. There will be no useful suggestions for https
   // or chrome URLs.
@@ skipping 166 matching lines @@
     // Style to look like normal search suggestions.
     match.contents_class.push_back(
        ACMatchClassification(0, ACMatchClassification::DIM));
     match.contents_class.push_back(
        ACMatchClassification(user_text_.length(), ACMatchClassification::NONE));
   }
   match.transition = content::PAGE_TRANSITION_GENERATED;
 
   matches_.push_back(match);
 }