Notify GCMAppHandlers when the store is reset, so they clear cached IDs

components/gcm_driver/fake_gcm_app_handler.cc

Index: components/gcm_driver/fake_gcm_app_handler.cc
diff --git a/components/gcm_driver/fake_gcm_app_handler.cc b/components/gcm_driver/fake_gcm_app_handler.cc
index 14a43f2e6e99cc31f1c5ea17a9a2fb46ec714a30..839312df3c7d1094da490e9d0638c65ebfbff007 100644
--- a/components/gcm_driver/fake_gcm_app_handler.cc
+++ b/components/gcm_driver/fake_gcm_app_handler.cc
@@ -24,6 +24,9 @@ void FakeGCMAppHandler::WaitForNotification() {
 void FakeGCMAppHandler::ShutdownHandler() {
 }
 
+void FakeGCMAppHandler::OnStoreReset() {
+}
+
 void FakeGCMAppHandler::OnMessage(const std::string& app_id,
                                   const IncomingMessage& message) {
   ClearResults();