Store default search provider data in dictionary pref.

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 e2dc86a5d87fda9a557120938123713964ff3f7a..46c8249e58be07e1542ac8089b1c8246642ba2d5 100644
--- a/chrome/browser/search_engines/template_url_service.h
+++ b/chrome/browser/search_engines/template_url_service.h
@@ -16,6 +16,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/prefs/pref_change_registrar.h"
+#include "chrome/browser/search_engines/default_search_manager.h"
 #include "chrome/browser/search_engines/template_url_id.h"
 #include "chrome/browser/webdata/web_data_service.h"
 #include "components/keyed_service/core/keyed_service.h"
@@ -776,6 +777,9 @@ class TemplateURLService : public WebDataServiceConsumer,
   // Stores a list of callbacks to be run after TemplateURLService has loaded.
   base::CallbackList<void(void)> on_loaded_callbacks_;
 
+  // Helper class to manage the default search engine.

[Peter Kasting, 2014/04/23 23:36:30]

Nit: "... This will be NULL when using the testing-specific constructor."

[Cait (Slow), 2014/04/24 14:53:39]

Done.

+  scoped_ptr<DefaultSearchManager> default_search_manager_;
+
   DISALLOW_COPY_AND_ASSIGN(TemplateURLService);
 };