Implemented 'Reset Search engines' feature.

chrome/browser/search_engines/template_url_service.h

Index: chrome/browser/search_engines/template_url_service.h
diff --git a/chrome/browser/search_engines/template_url_service.h b/chrome/browser/search_engines/template_url_service.h
index adabac778c8c5e51b3ecc9ae8e756b82eb39250a..83826d573b82778d82697ef2c52776c62b05eae0 100644
--- a/chrome/browser/search_engines/template_url_service.h
+++ b/chrome/browser/search_engines/template_url_service.h
@@ -225,6 +225,11 @@ class TemplateURLService : public WebDataServiceConsumer,
   // destroyed at any time so should be used right after the call.
   TemplateURL* FindNewDefaultSearchProvider();
 
+  // Resets the search providers to the prepopulated engines plus any
+  // extension-supplied engines.  Also resets the default search engine unless
+  // it's managed.
+  void ResetNonExtensionURLs();
+
   // Observers used to listen for changes to the model.
   // TemplateURLService does NOT delete the observers when deleted.
   void AddObserver(TemplateURLServiceObserver* observer);
@@ -421,6 +426,9 @@ class TemplateURLService : public WebDataServiceConsumer,
       scoped_ptr<TemplateURL>* default_provider,
       bool* is_managed);
 
+  // Clears user preferences describing the default search engine.
+  void ClearDefaultProviderFromPrefs();
+
   // Returns true if there is no TemplateURL that has a search url with the
   // specified host, or the only TemplateURLs matching the specified host can
   // be replaced.
@@ -582,6 +590,17 @@ class TemplateURLService : public WebDataServiceConsumer,
 
   void OnSyncedDefaultSearchProviderGUIDChanged();
 
+  // Adds |template_urls| to |template_urls_| and sets up the default search
+  // provider.  If |default_search_provider| is non-NULL, it must refer to one
+  // of the |template_urls|, and will be used as the new default.
+  void AddTemplateURLsAndSetupDefaultEngine(
+      TemplateURLVector* template_urls,
+      TemplateURL* default_search_provider);
+
+  // If there is no current default search provider, sets the default to the
+  // result of calling FindNewDefaultSearchProvider().
+  void EnsureDefaultSearchProviderExists();
+
   content::NotificationRegistrar notification_registrar_;
   PrefChangeRegistrar pref_change_registrar_;