App Host install should not be triggered by component extensions.

chrome/browser/extensions/app_shortcut_manager.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/browser/extensions/app_shortcut_manager.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
@@ skipping 70 matching lines @@
 }
 
 void AppShortcutManager::Observe(int type,
                                  const content::NotificationSource& source,
                                  const content::NotificationDetails& details) {
 #if !defined(OS_MACOSX)
   switch (type) {
     case chrome::NOTIFICATION_EXTENSION_INSTALLED: {
       const Extension* extension = content::Details<const Extension>(
           details).ptr();
-      if (extension->is_platform_app()) {
+      if (extension->is_platform_app() &&
+          extension->location() != Extension::COMPONENT) {
 #if defined(OS_WIN)
         if (BrowserDistribution::GetDistribution()->AppHostIsSupported()) {
           scoped_refptr<Extension> extension_ref(const_cast<Extension*>(
               extension));
           extensions::AppHostInstaller::EnsureAppHostInstalled(
               base::Bind(&AppShortcutManager::OnAppHostInstallationComplete,
                          weak_factory_.GetWeakPtr(), extension_ref));
         } else {
           UpdateApplicationShortcuts(extension);
         }
@@ skipping 72 matching lines @@
 }
 
 void AppShortcutManager::DeleteApplicationShortcuts(
     const Extension* extension) {
   ShellIntegration::ShortcutInfo delete_info =
       ShortcutInfoForExtensionAndProfile(extension, profile_);
   web_app::DeleteAllShortcuts(delete_info);
 }
 
 }  // namespace extensions