AppShell support for Mac.

extensions/shell/browser/shell_browser_main_parts_mac.mm

Index: extensions/shell/browser/shell_browser_main_parts_mac.mm
diff --git a/extensions/shell/browser/shell_browser_main_parts_mac.mm b/extensions/shell/browser/shell_browser_main_parts_mac.mm
new file mode 100644
index 0000000000000000000000000000000000000000..9fe902dc3c9e211908d5d6a32217a36e98a5814a
--- /dev/null
+++ b/extensions/shell/browser/shell_browser_main_parts_mac.mm
@@ -0,0 +1,16 @@
+// Copyright 2014 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 "extensions/shell/browser/shell_browser_main_parts.h"
+
+#import "content/shell/browser/shell_application_mac.h"
+
+namespace extensions {
+
+void MainPartsPreMainMessageLoopStartMac() {
+  // Force the NSApplication subclass to be used.
+  [ShellCrApplication sharedApplication];
+}
+
+}  // namespace extensions