Applied review comments from oshima for CL 7850026.

chrome/browser/process_singleton.h

 // Copyright (c) 2011 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_
 #pragma once
 
 #include "build/build_config.h"
 
@@ skipping 110 matching lines @@
  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.
   static const int kTimeoutInSeconds = 20;
 #endif
 
   bool locked_;
   gfx::NativeWindow foreground_window_;
 
-#if defined(OS_WIN)
+#if defined(USE_AURA)
+  // TODO(saintlou): The process_singleton_aura.cc is still a stub.
+#elif defined(OS_WIN)
   // This ugly behemoth handles startup commands sent from another process.
   LRESULT OnCopyData(HWND hwnd, const COPYDATASTRUCT* cds);
 
   LRESULT CALLBACK WndProc(HWND hwnd,
                            UINT message,
                            WPARAM wparam,
                            LPARAM lparam);
 
   static LRESULT CALLBACK WndProcStatic(HWND hwnd,
                                         UINT message,
@@ skipping 17 matching lines @@
   FilePath lock_path_;
 
   // Path in file system to the cookie file.
   FilePath cookie_path_;
 
   // Temporary directory to hold the socket.
   ScopedTempDir socket_dir_;
 
   // Helper class for linux specific messages.  LinuxWatcher is ref counted
   // because it posts messages between threads.
-#if !defined(USE_AURA)
   class LinuxWatcher;
   scoped_refptr<LinuxWatcher> watcher_;
-#endif
 #elif defined(OS_MACOSX)
   // Path in file system to the lock.
   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_