Add a new app API to enable watchdog behavior restarts in kiosk apps

extensions/browser/test_extensions_browser_client.h

Index: extensions/browser/test_extensions_browser_client.h
diff --git a/extensions/browser/test_extensions_browser_client.h b/extensions/browser/test_extensions_browser_client.h
index e66fe98910ef7c1c5ff974fd74bf1c503132fba2..64cebf82cca6b334f3a5a68ddda016e21dc99f4d 100644
--- a/extensions/browser/test_extensions_browser_client.h
+++ b/extensions/browser/test_extensions_browser_client.h
@@ -114,6 +114,10 @@ class TestExtensionsBrowserClient : public ExtensionsBrowserClient {
   scoped_refptr<update_client::UpdateClient> CreateUpdateClient(
       content::BrowserContext* context) override;
 
+  ExtensionSystemProvider* extension_system_factory() {
+    return extension_system_factory_;
+  }
+
  private:
   content::BrowserContext* main_context_;       // Not owned.
   content::BrowserContext* incognito_context_;  // Not owned, defaults to NULL.