Uninstall Chrome + has App Host + not App Launcher => Uninstall App Host.

chrome/installer/setup/install.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 "chrome/installer/setup/install.h"
 
 #include <windows.h>
 #include <shlobj.h>
 #include <time.h>
 #include <winuser.h>
@@ skipping 277 matching lines @@
 
 // Returns the appropriate shortcut operations for App Launcher,
 // based on state of installation and master_preferences.
 installer::InstallShortcutOperation GetAppLauncherShortcutOperation(
     const InstallationState& original_state,
     const InstallerState& installer_state) {
   const installer::ProductState* original_app_host_state =
       original_state.GetProductState(installer_state.system_install(),
                                      BrowserDistribution::CHROME_APP_HOST);
   bool app_launcher_exists = original_app_host_state &&
-      CommandLine(original_app_host_state->uninstall_command())
+      original_app_host_state->uninstall_command()
           .HasSwitch(installer::switches::kChromeAppLauncher);
   if (!app_launcher_exists)
     return installer::INSTALL_SHORTCUT_CREATE_ALL;
 
   return installer::INSTALL_SHORTCUT_REPLACE_EXISTING;
 }
 
 }  // end namespace
 
 namespace installer {
@@ skipping 375 matching lines @@
            INSTALL_SHORTCUT_CREATE_EACH_IF_NO_SYSTEM_LEVEL);
 
   // Read master_preferences copied beside chrome.exe at install.
   MasterPreferences prefs(installation_root.AppendASCII(kDefaultMasterPrefs));
   FilePath chrome_exe(installation_root.Append(kChromeExe));
   CreateOrUpdateShortcuts(
       chrome_exe, chrome, prefs, CURRENT_USER, install_operation);
 }
 
 }  // namespace installer