Implemented 'Reset Search engines' feature.

chrome/browser/search_engines/template_url_prepopulate_data.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/search_engines/template_url_prepopulate_data.h"
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 #include <locale.h>
 #endif
 
@@ skipping 1179 matching lines @@
       engine->GetList("alternate_urls", &alternate_urls);
       engine->GetString("search_terms_replacement_key",
           &search_terms_replacement_key);
       t_urls->push_back(MakePrepopulatedTemplateURL(profile, name, keyword,
           search_url, suggest_url, instant_url, favicon_url, encoding,
           *alternate_urls, search_terms_replacement_key, id));
     }
   }
 }
 
+void ClearPrepopulatedEnginesInPrefs(Profile* profile) {
+  if (!profile)
+    return;
+
+  PrefService* prefs = profile->GetPrefs();
+  DCHECK(prefs);
+  const PrefService::Preference* pref =
+      prefs->FindPreference(prefs::kSearchProviderOverrides);
+  if (pref && pref->HasUserSetting()) {
+    ListValue empty_list;
+    prefs->Set(prefs::kSearchProviderOverrides, empty_list);

[battre, 2013/05/22 14:03:37]

Should we use prefs->ClearPref here and in the following line? 

[vasilii, 2013/05/22 18:54:08]

Done.

+    prefs->SetInteger(prefs::kSearchProviderOverridesVersion,
+                      kCurrentDataVersion);
+  }
+}
+
 // The caller owns the returned TemplateURL.
 TemplateURL* MakePrepopulatedTemplateURLFromPrepopulateEngine(
     Profile* profile,
     const PrepopulatedEngine& engine) {
 
   ListValue alternate_urls;
   if (engine.alternate_urls) {
     for (size_t i = 0; i < engine.alternate_urls_size; ++i)
       alternate_urls.AppendString(std::string(engine.alternate_urls[i]));
   }
@@ skipping 81 matching lines @@
 GURL GetLogoURL(const TemplateURL& template_url, LogoSize size) {
   if (GetEngineType(template_url.url()) == SEARCH_ENGINE_GOOGLE) {
     return GURL((size == LOGO_200_PERCENT) ?
                 google_logos.logo_200_percent_url :
                 google_logos.logo_100_percent_url);
   }
   return GURL();
 }
 
 }  // namespace TemplateURLPrepopulateData