Revert 285661 "Remove some dead app host code."

trunk/src/chrome/installer/launcher_support/chrome_launcher_support.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_LAUNCHER_SUPPORT_CHROME_LAUNCHER_SUPPORT_H_
 #define CHROME_INSTALLER_LAUNCHER_SUPPORT_CHROME_LAUNCHER_SUPPORT_H_
 
 namespace base {
 class FilePath;
 }
 
 namespace chrome_launcher_support {
 
 enum InstallationLevel {
   USER_LEVEL_INSTALLATION,
   SYSTEM_LEVEL_INSTALLATION,
 };
 
+enum InstallationState {
+  NOT_INSTALLED,
+  INSTALLED_AT_USER_LEVEL,
+  INSTALLED_AT_SYSTEM_LEVEL,
+};
+
+// The app GUID for Chrome App Launcher.
+extern const wchar_t kAppLauncherGuid[];
+
+// Returns the path to an existing setup.exe at the specified level, if it can
+// be found via Omaha client state.
+base::FilePath GetSetupExeForInstallationLevel(InstallationLevel level);
+
 // Returns the path to an installed chrome.exe at the specified level, if it can
 // be found via Omaha client state. Prefers the installer from a multi-install,
 // but may also return that of a single-install of Chrome if no multi-install
 // exists.
 base::FilePath GetChromePathForInstallationLevel(InstallationLevel level);
 
+// Returns the path to an installed app_host.exe at the specified level, if
+// it can be found via Omaha client state.
+base::FilePath GetAppHostPathForInstallationLevel(InstallationLevel level);
+
+// Returns the path to an installed SxS chrome.exe at the specified level, if
+// it can be found via Omaha client state.
+base::FilePath GetChromeSxSPathForInstallationLevel(InstallationLevel level);
+
 // Returns the path to an installed chrome.exe, or an empty path. Prefers a
 // system-level installation to a user-level installation. Uses Omaha client
 // state to identify a Chrome installation location.
 // The file path returned (if any) is guaranteed to exist.
 base::FilePath GetAnyChromePath();
 
+// Returns the path to an installed app_host.exe, or an empty path. Prefers a
+// system-level installation to a user-level installation. Uses Omaha client
+// state to identify a App Host installation location.
+// The file path returned (if any) is guaranteed to exist.
+base::FilePath GetAnyAppHostPath();
+
+// Returns the path to an installed SxS chrome.exe, or an empty path. Prefers a
+// user-level installation to a system-level installation. Uses Omaha client
+// state to identify a Chrome Canary installation location.
+// The file path returned (if any) is guaranteed to exist.
+base::FilePath GetAnyChromeSxSPath();
+
+// Uninstalls the legacy app launcher by launching setup.exe with the uninstall
+// arguments from the App Launcher ClientState registry key. The uninstall will
+// run asynchronously.
+void UninstallLegacyAppLauncher(InstallationLevel level);
+
+// Returns true if App Host is installed (system-level or user-level),
+// or in the same directory as the current executable.
+bool IsAppHostPresent();
+
+// Returns the app launcher installation state. If the launcher is installed
+// at both system level and user level, system level is returned.
+InstallationState GetAppLauncherInstallationState();
+
+// Returns true if App Launcher is installed (system-level or user-level).
+bool IsAppLauncherPresent();
+
+// Returns true if the Chrome browser is installed (system-level or user-level).
+// If this is running in an official build, it will check if a non-canary build
+// if installed. If it is not an official build, it will always return true.
+bool IsChromeBrowserPresent();
+
 }  // namespace chrome_launcher_support
 
 #endif  // CHROME_INSTALLER_LAUNCHER_SUPPORT_CHROME_LAUNCHER_SUPPORT_H_