Resolve the conflict that auto-launch has with the background mode feature (part 1).

chrome/installer/util/auto_launch_util.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_INSTALLER_UTIL_AUTO_LAUNCH_UTIL_H_
 #define CHROME_INSTALLER_UTIL_AUTO_LAUNCH_UTIL_H_
 #pragma once
 
 #include "base/string16.h"
 
 class FilePath;
 
 // A namespace containing the platform specific implementation of setting Chrome
 // to launch on computer startup.
 namespace auto_launch_util {
 
+// We use one Run key with flags specifying which feature we want to start up.
+// When we change our Run key we need to specify what we want to do with each
+// flag. This lists the possible actions we can take with the flags.
+enum FlagSetting {
+  FLAG_DISABLE,   // Disable the flag.
+  FLAG_ENABLE,    // Enable the flag.
+  FLAG_PRESERVE,  // Preserve the value that the flag has currently.
+};
+
 // Returns whether the Chrome executable specified in |application_path| is set
-// to auto-launch at computer startup. NOTE: |application_path| is optional and
-// should be blank in most cases (as it will default to the application path of
-// the current executable). |profile_directory| is the name of the directory
-// (leaf, not the full path) that contains the profile that should be opened at
-// computer startup.
-bool WillLaunchAtLogin(const FilePath& application_path,
-                       const string16& profile_directory);
+// to auto-launch at computer startup with a given |command_line_switch|.
+// NOTE: |application_path| is optional and should be blank in most cases (as
+// it will default to the application path of the current executable).
+// |profile_directory| is the name of the directory (leaf, not the full path)
+// that contains the profile that should be opened at computer startup.
+// |command_line_switch| is the switch we are optionally interested in and, if
+// not blank, must be present for the function to return true.
+bool WillLaunchAtLoginWithSwitch(const FilePath& application_path,
+                                 const string16& profile_directory,
+                                 const std::string& command_line_switch);
 
-// Configures whether the Chrome executable should auto-launch at computer
-// startup. |application_path| is needed when |auto_launch| is true AND when
-// the caller is not the process being set to auto-launch, ie. the installer.
-// This is because |application_path|, if left blank, defaults to the
-// application path of the current executable. If |auto_launch| is true, then it
-// will auto-launch, otherwise it will be configured not to. |profile_directory|
-// is the name of the directory (leaf, not the full path) that contains the
-// profile that should be opened at computer startup.
-void SetWillLaunchAtLogin(bool auto_launch,
-                          const FilePath& application_path,
-                          const string16& profile_directory);
+// Configures which flag should be present when the Chrome executable
+// auto-launches at computer startup. |application_path| is needed when one or
+// more flags is being set AND when the caller is not the process being set to
+// auto-launch, ie. the installer. This is because |application_path|, if left
+// blank, defaults to the application path of the current executable.
+// |profile_directory| is the name of the directory (leaf, not the full path)
+// that contains the profile that should be opened at computer startup.
+// |auto_start_feature| is the feature that launches Chrome with a window at
+// computer startup. |background_mode| launches Chrome in the background without
+// a window. If both |background_mode| and |auto_start_feature| are enabled, the
+// |auto_start_feature| will win and a window will be shown. We don't remove the
+// |background_mode| flag when |auto_start_feature| is turned on because the
+// user might turn off auto_start at any time from the settings page, leaving
+// only |background_mode|.
+void SetWillLaunchAtLogin(const FilePath& application_path,
+                          const string16& profile_directory,
+                          FlagSetting auto_start_feature,
+                          FlagSetting background_mode);
 
 }  // namespace auto_launch_util
 
 #endif  // CHROME_INSTALLER_UTIL_AUTO_LAUNCH_UTIL_H_