Add a Restore() method to ValueStore and make StorageAPI use it

chrome/browser/extensions/test_extension_system.cc

Index: chrome/browser/extensions/test_extension_system.cc
diff --git a/chrome/browser/extensions/test_extension_system.cc b/chrome/browser/extensions/test_extension_system.cc
index 416ca664f742d9a27643eb17cc8009d7d01eaffd..67e522a8a8f41e7c2055e8c4c5c263f786ebebb3 100644
--- a/chrome/browser/extensions/test_extension_system.cc
+++ b/chrome/browser/extensions/test_extension_system.cc
@@ -152,10 +152,12 @@ TestExtensionSystem::lazy_background_task_queue() {
   return NULL;
 }
 
-EventRouter* TestExtensionSystem::event_router() {
-  return NULL;
+void TestExtensionSystem::SetEventRouter(scoped_ptr<EventRouter> event_router) {
+  event_router_.reset(event_router.release());
 }
 
+EventRouter* TestExtensionSystem::event_router() { return event_router_.get(); }
+
 ExtensionWarningService* TestExtensionSystem::warning_service() {
   return NULL;
 }