Refactor ProcessSingleton so that it may be used distinctly from a full browser process.

chrome/browser/process_singleton_mac.cc

 // 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.
 
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/file.h>
 
 #include "chrome/browser/process_singleton.h"
 
@@ skipping 38 matching lines @@
   // Make sure the lock is released.  Process death will also release
   // it, even if this is not called.
   Cleanup();
 }
 
 ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcess() {
   // This space intentionally left blank.
   return PROCESS_NONE;
 }
 
-ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessOrCreate() {
+ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessOrCreate(
+    const NotificationCallback& notification_callback) {
   // Windows tries NotifyOtherProcess() first.
-  return Create() ? PROCESS_NONE : PROFILE_IN_USE;
+  return Create(notification_callback) ? PROCESS_NONE : PROFILE_IN_USE;
 }
 
 // Attempt to acquire an exclusive lock on an empty file in the
 // profile directory.  Returns |true| if it gets the lock.  Returns
 // |false| if the lock is held, or if there is an error.
+// |notification_callback| is not actually used. See the comments at the top of
+// this file for details.
 // TODO(shess): Rather than logging failures, popup an alert.  Punting
 // that for now because it would require confidence that this code is
 // never called in a situation where an alert wouldn't work.
 // http://crbug.com/59061
-bool ProcessSingleton::Create() {
+bool ProcessSingleton::Create(
+    const NotificationCallback& notification_callback) {
   DCHECK_EQ(-1, lock_fd_) << "lock_path_ is already open.";
 
   lock_fd_ = HANDLE_EINTR(open(lock_path_.value().c_str(),
                                O_RDONLY | O_CREAT, 0644));
   if (lock_fd_ == -1) {
     const int capture_errno = errno;
     DPCHECK(lock_fd_ != -1) << "Unexpected failure opening profile lockfile";
     UMA_HISTOGRAM_ENUMERATION("ProcessSingleton.OpenError",
                               capture_errno, kMaxErrno);
     return false;
@@ skipping 25 matching lines @@
 }
 
 void ProcessSingleton::Cleanup() {
   // Closing the file also releases the lock.
   if (lock_fd_ != -1) {
     int rc = HANDLE_EINTR(close(lock_fd_));
     DPCHECK(!rc) << "Closing lock_fd_:";
   }
   lock_fd_ = -1;
 }
-
-void ProcessSingleton::ProcessCommandLine(const CommandLine& command_line,
-                                          const FilePath& current_directory) {
-}