Implement kiosk multiple apps feature.

chrome/browser/chromeos/app_mode/kiosk_app_manager.cc

Index: chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
diff --git a/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc b/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
index a37df89e7ee7638bc03f773960b6e5dadaf6f6b4..d590ff30790d25026027c9ad026b068e5cb4054f 100644
--- a/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
+++ b/chrome/browser/chromeos/app_mode/kiosk_app_manager.cc
@@ -465,7 +465,7 @@ void KioskAppManager::RemoveObserver(KioskAppManagerObserver* observer) {
 extensions::ExternalLoader* KioskAppManager::CreateExternalLoader() {
   if (external_loader_created_) {
     NOTREACHED();
-    return NULL;
+    return nullptr;
   }
   external_loader_created_ = true;
   KioskAppExternalLoader* loader = new KioskAppExternalLoader();
@@ -474,6 +474,19 @@ extensions::ExternalLoader* KioskAppManager::CreateExternalLoader() {
   return loader;
 }
 
+extensions::ExternalLoader*
+KioskAppManager::CreateSecondaryAppExternalLoader() {
+  if (secondary_app_external_loader_created_) {
+    NOTREACHED();
+    return nullptr;
+  }
+  secondary_app_external_loader_created_ = true;
+  KioskAppExternalLoader* secondary_loader = new KioskAppExternalLoader();
+  secondary_app_external_loader_ = secondary_loader->AsWeakPtr();
+
+  return secondary_loader;
+}
+
 void KioskAppManager::InstallFromCache(const std::string& id) {
   const base::DictionaryValue* extension = NULL;
   if (external_cache_->cached_extensions()->GetDictionary(id, &extension)) {
@@ -487,6 +500,25 @@ void KioskAppManager::InstallFromCache(const std::string& id) {
   }
 }
 
+void KioskAppManager::InstallSecondaryApps(
+    const std::vector<std::string>& ids) {
+  if (ids.empty())
+    return;
+
+  scoped_ptr<base::DictionaryValue> prefs(new base::DictionaryValue);
+  for (const std::string& id : ids) {
+    scoped_ptr<base::DictionaryValue> extension_entry(
+        new base::DictionaryValue);
+    extension_entry->SetStringWithoutPathExpansion(
+        extensions::ExternalProviderImpl::kExternalUpdateUrl,
+        extension_urls::GetWebstoreUpdateUrl().spec());
+    extension_entry->SetBoolean(
+        extensions::ExternalProviderImpl::kIsFromWebstore, true);
+    prefs->Set(id, extension_entry.Pass());
+  }
+  secondary_app_external_loader_->SetCurrentAppExtensions(prefs.Pass());
+}
+
 void KioskAppManager::UpdateExternalCache() {
   UpdateAppData();
 }
@@ -511,7 +543,9 @@ void KioskAppManager::PutValidatedExternalExtension(
 }
 
 KioskAppManager::KioskAppManager()
-    : ownership_established_(false), external_loader_created_(false) {
+    : ownership_established_(false),
+      external_loader_created_(false),
+      secondary_app_external_loader_created_(false) {
   base::FilePath cache_dir;
   GetCrxCacheDir(&cache_dir);
   external_cache_.reset(