[win] Add signin support for the app launcher.

ui/app_list/signin_delegate.cc

Index: ui/app_list/signin_delegate.cc
diff --git a/ui/app_list/signin_delegate.cc b/ui/app_list/signin_delegate.cc
new file mode 100644
index 0000000000000000000000000000000000000000..51eb8305019e26747516a27bf15b758b4b512321
--- /dev/null
+++ b/ui/app_list/signin_delegate.cc
@@ -0,0 +1,27 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/app_list/signin_delegate.h"
+#include "ui/app_list/signin_delegate_observer.h"
+
+namespace app_list {
+
+SigninDelegate::SigninDelegate() {}
+
+SigninDelegate::~SigninDelegate() {}
+
+void SigninDelegate::AddObserver(SigninDelegateObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void SigninDelegate::RemoveObserver(SigninDelegateObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void SigninDelegate::NotifySigninSuccess() {
+  FOR_EACH_OBSERVER(app_list::SigninDelegateObserver, observers_,
+                    OnSigninSuccess());
+}
+
+}  // namespace app_list