mac: Load the system hotkeys after launch. (reland)

content/browser/cocoa/system_hotkey_helper_mac.h

+// 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.
+
+#ifndef CONTENT_BROWSER_COCOA_SYSTEM_HOTKEY_HELPER_MAC_H_
+#define CONTENT_BROWSER_COCOA_SYSTEM_HOTKEY_HELPER_MAC_H_
+
+#include "base/memory/singleton.h"
+#include "base/memory/weak_ptr.h"
+
+#ifdef __OBJC__
+@class NSDictionary;
+#else
+class NSDictionary;
+#endif
+
+namespace content {
+
+class SystemHotkeyMap;
+
+// This singleton holds a global mapping of hotkeys reserved by OSX.
+class SystemHotkeyHelperMac {
+ public:
+  // Return pointer to the singleton instance for the current process.
+  static SystemHotkeyHelperMac* GetInstance();
+
+  // Loads the system hot keys after a brief delay, to reduce file system access
+  // immediately after launch.
+  void DeferredLoadSystemHotkeys();
+
+  // Guaranteed to not be NULL.
+  SystemHotkeyMap* map() { return map_.get(); }
+
+ private:
+  friend struct DefaultSingletonTraits<SystemHotkeyHelperMac>;
+
+  SystemHotkeyHelperMac();
+  ~SystemHotkeyHelperMac();
+
+  // Must be called from the FILE thread. Loads the file containing the system
+  // hotkeys into a NSDictionary* object, and passes the result to FileDidLoad
+  // on the UI thread.
+  void LoadSystemHotkeys();
+
+  // Must be called from the UI thread.  This takes ownership of |dictionary|.
+  // Parses the system hotkeys from the plist stored in |dictionary|.
+  void FileDidLoad(NSDictionary* dictionary);
+
+  scoped_ptr<SystemHotkeyMap> map_;
+
+  DISALLOW_COPY_AND_ASSIGN(SystemHotkeyHelperMac);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_COCOA_SYSTEM_HOTKEY_HELPER_MAC_H_