Use process_singleton_linux on Mac.

chrome/browser/process_singleton.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_BROWSER_PROCESS_SINGLETON_H_
 #define CHROME_BROWSER_PROCESS_SINGLETON_H_
 
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif  // defined(OS_WIN)
 
 #include <set>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/process/process.h"
 #include "base/threading/non_thread_safe.h"
 #include "ui/gfx/native_widget_types.h"
 
-#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
+#if defined(OS_POSIX) && !defined(OS_ANDROID)
 #include "base/files/scoped_temp_dir.h"
 #endif
 
 #if defined(OS_WIN)
 #include "base/win/message_window.h"
 #endif  // defined(OS_WIN)
 
 namespace base {
 class CommandLine;
 }
@@ skipping 44 matching lines @@
   // false is returned, we are not the singleton instance and the caller must
   // exit.
   // NOTE: Most callers should generally prefer NotifyOtherProcessOrCreate() to
   // this method, only callers for whom failure is prefered to notifying another
   // process should call this directly.
   bool Create();
 
   // Clear any lock state during shutdown.
   void Cleanup();
 
-#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
+#if defined(OS_POSIX) && !defined(OS_ANDROID)
   static void DisablePromptForTesting();
 #endif
 
  protected:
   // Notify another process, if available.
   // Returns true if another process was found and notified, false if we should
   // continue with the current process.
   // On Windows, Create() has to be called before this.
   NotifyResult NotifyOtherProcess();
 
-#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
+#if defined(OS_POSIX) && !defined(OS_ANDROID)
   // Exposed for testing.  We use a timeout on Linux, and in tests we want
   // this timeout to be short.
   NotifyResult NotifyOtherProcessWithTimeout(
       const base::CommandLine& command_line,
       int timeout_seconds,
       bool kill_unresponsive);
   NotifyResult NotifyOtherProcessWithTimeoutOrCreate(
       const base::CommandLine& command_line,
       int timeout_seconds);
   void OverrideCurrentPidForTesting(base::ProcessId pid);
   void OverrideKillCallbackForTesting(
       const base::Callback<void(int)>& callback);
 #endif
 
  private:
-#if !defined(OS_MACOSX)
   // Timeout for the current browser process to respond. 20 seconds should be
-  // enough. It's only used in Windows and Linux implementations.
+  // enough.
   static const int kTimeoutInSeconds = 20;
-#endif
 
   NotificationCallback notification_callback_;  // Handler for notifications.
 
 #if defined(OS_WIN)
   bool EscapeVirtualization(const base::FilePath& user_data_dir);
 
   HWND remote_window_;  // The HWND_MESSAGE of another browser.
   base::win::MessageWindow window_;  // The message-only window.
   bool is_virtualized_;  // Stuck inside Microsoft Softricity VM environment.
   HANDLE lock_file_;
   base::FilePath user_data_dir_;
-#elif defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
+#elif defined(OS_POSIX) && !defined(OS_ANDROID)
   // Return true if the given pid is one of our child processes.
   // Assumes that the current pid is the root of all pids of the current
   // instance.
   bool IsSameChromeInstance(pid_t pid);
 
   // Extract the process's pid from a symbol link path and if it is on
   // the same host, kill the process, unlink the lock file and return true.
   // If the process is part of the same chrome instance, unlink the lock file
   // and return true without killing it.
   // If the process is on a different host, return false.
@@ skipping 18 matching lines @@
   // Path in file system to the cookie file.
   base::FilePath cookie_path_;
 
   // Temporary directory to hold the socket.
   base::ScopedTempDir socket_dir_;
 
   // Helper class for linux specific messages.  LinuxWatcher is ref counted
   // because it posts messages between threads.
   class LinuxWatcher;
   scoped_refptr<LinuxWatcher> watcher_;
-#elif defined(OS_MACOSX)
-  // Path in file system to the lock.
-  base::FilePath lock_path_;
-
-  // File descriptor associated with the lockfile, valid between
-  // |Create()| and |Cleanup()|.  Two instances cannot have a lock on
-  // the same file at the same time.
-  int lock_fd_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ProcessSingleton);
 };
 
 #endif  // CHROME_BROWSER_PROCESS_SINGLETON_H_