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

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_
 #pragma once
 
 #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/file_path.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/threading/non_thread_safe.h"
 #include "ui/gfx/native_widget_types.h"
 
 #if defined(OS_POSIX)
 #include "base/file_path.h"
 #endif  // defined(OS_POSIX)
@@ skipping 18 matching lines @@
 
 class ProcessSingleton : public base::NonThreadSafe {
  public:
   enum NotifyResult {
     PROCESS_NONE,
     PROCESS_NOTIFIED,
     PROFILE_IN_USE,
     LOCK_ERROR,
   };
 
+  // Implement this callback to handle notifications from other processes. The
+  // callback will receive the command line and directory with which the other
+  // Chrome process was launched. Return true if the command line will be
+  // handled within the current browser instance or false if the remote process
+  // should handle it (i.e., because the current process is shutting down).
+  typedef base::Callback<
+      bool(const CommandLine& command_line, const FilePath& current_directory)>
+      NotificationCallback;
+
   explicit ProcessSingleton(const FilePath& user_data_dir);
   ~ProcessSingleton();
 
   // Notify another process, if available.
   // Returns true if another process was found and notified, false if we
   // should continue with this process.
   // Windows code roughly based on Mozilla.
   //
   // TODO(brettw): this will not handle all cases. If two process start up too
   // close to each other, the Create() might not yet have happened for the
   // first one, so this function won't find it.
   NotifyResult NotifyOtherProcess();
 
-  // Notify another process, if available.  Otherwise sets ourselves as the
-  // singleton instance.  Returns PROCESS_NONE if we became the singleton
+  // Notify another process, if available. Otherwise sets ourselves as the
+  // singleton instance and stores the provided callback for notification from
+  // future processes. Returns PROCESS_NONE if we became the singleton
   // instance.
-  NotifyResult NotifyOtherProcessOrCreate();
+  NotifyResult NotifyOtherProcessOrCreate(
+      const NotificationCallback& notification_callback);
 
 #if defined(OS_LINUX) || defined(OS_OPENBSD)
   // Exposed for testing.  We use a timeout on Linux, and in tests we want
   // this timeout to be short.
   NotifyResult NotifyOtherProcessWithTimeout(const CommandLine& command_line,
                                              int timeout_seconds,
                                              bool kill_unresponsive);
   NotifyResult NotifyOtherProcessWithTimeoutOrCreate(
       const CommandLine& command_line,
+      const NotificationCallback& notification_callback,
       int timeout_seconds);
 #endif  // defined(OS_LINUX) || defined(OS_OPENBSD)
 
 #if defined(OS_WIN) && !defined(USE_AURA)
   // Used in specific cases to let us know that there is an existing instance
   // of Chrome running with this profile. In general, you should not use this
   // function. Instead consider using NotifyOtherProcessOrCreate().
   // For non profile-specific method, use
   // browser_util::IsBrowserAlreadyRunning().
   bool FoundOtherProcessWindow() const {
       return (NULL != remote_window_);
   }
 #endif  // defined(OS_WIN)
 
   // Sets ourself up as the singleton instance.  Returns true on success.  If
   // false is returned, we are not the singleton instance and the caller must
-  // exit.
-  bool Create();
+  // exit. Otherwise, stores the provided callback for notification from
+  // future processes.
+  bool Create(
+      const NotificationCallback& notification_callback);
 
   // Clear any lock state during shutdown.
   void Cleanup();
 
   // Blocks the dispatch of CopyData messages. foreground_window refers
   // to the window that should be set to the foreground if a CopyData message
   // is received while the ProcessSingleton is locked.
   void Lock(gfx::NativeWindow foreground_window) {
     DCHECK(CalledOnValidThread());
     locked_ = true;
@@ skipping 14 matching lines @@
     DCHECK(CalledOnValidThread());
     return locked_;
   }
 
 #if defined(OS_WIN)
   LRESULT WndProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam);
 #endif
 
  private:
   typedef std::pair<CommandLine::StringVector, FilePath> DelayedStartupMessage;
-  void ProcessCommandLine(const CommandLine& command_line,
-                          const FilePath& current_directory);
 
 #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_;
+  NotificationCallback notification_callback_;  // Handler for notifications.
 
 #if defined(OS_WIN)
   // This ugly behemoth handles startup commands sent from another process.
   LRESULT OnCopyData(HWND hwnd, const COPYDATASTRUCT* cds);
 
   bool EscapeVirtualization(const FilePath& user_data_dir);
 
   HWND remote_window_;  // The HWND_MESSAGE of another browser.
   HWND window_;  // The HWND_MESSAGE window.
   bool is_virtualized_;  // Stuck inside Microsoft Softricity VM environment.
@@ skipping 25 matching lines @@
 #endif
 
   // If messages are received in the locked state, the corresponding command
   // lines are saved here to be replayed later.
   std::vector<DelayedStartupMessage> saved_startup_messages_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessSingleton);
 };
 
 #endif  // CHROME_BROWSER_PROCESS_SINGLETON_H_