Put app shim IPC socket in a temporary directory. (Mac)

chrome/common/mac/app_mode_common.h

 // Copyright (c) 2012 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 CHROME_COMMON_MAC_APP_MODE_COMMON_H_
 #define CHROME_COMMON_MAC_APP_MODE_COMMON_H_
 
 #import <Foundation/Foundation.h>
 
 #include "base/files/file_path.h"
@@ skipping 109 matching lines @@
   // URL for the shortcut. Must be a valid URL.
   std::string app_mode_url;  // Required: v1.0
 
   // Path to the app's user data directory.
   base::FilePath user_data_dir;
 
   // Directory of the profile associated with the app.
   base::FilePath profile_dir;
 };
 
+// Due to kernel API restraints on the length of the path to a socket, we
+// cannot use a socket under the user data dir. GetShortSocketPath returns a
+// path under /tmp constructed from a hash of the user data dir.
+base::FilePath GetShortSocketPath(const base::FilePath& user_data_dir);
+
 }  // namespace app_mode
 
 #endif  // CHROME_COMMON_MAC_APP_MODE_COMMON_H_