Make extensions DSE persistent in browser prefs

chrome/browser/search_engines/template_url_service_sync_unittest.cc

Index: chrome/browser/search_engines/template_url_service_sync_unittest.cc
diff --git a/chrome/browser/search_engines/template_url_service_sync_unittest.cc b/chrome/browser/search_engines/template_url_service_sync_unittest.cc
index 225a51d7c0835008616c5925300c6e9d9b5b184d..d394f00d0d3d1017d0fe16c295be0bfbdd7e34e0 100644
--- a/chrome/browser/search_engines/template_url_service_sync_unittest.cc
+++ b/chrome/browser/search_engines/template_url_service_sync_unittest.cc
@@ -165,6 +165,9 @@ class TestTemplateURLServiceClient : public TemplateURLServiceClient {
        const base::string16& term) override {}
    void AddKeywordGeneratedVisit(const GURL& url) override {}
    bool IsOmniboxExtensionURL(const std::string& url) override { return false; }
+   void SetExtensionControlledPref(
+      const std::string extension_id, const std::string pref_name,
+      std::unique_ptr<base::Value> pref_value) override {}
 };
 
 }  // namespace