Implement kiosk multiple apps feature.

chrome/browser/extensions/extension_service.cc

 // Copyright (c) 2013 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/extension_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 
@@ skipping 184 matching lines @@
 bool ExtensionService::OnExternalExtensionUpdateUrlFound(
     const std::string& id,
     const std::string& install_parameter,
     const GURL& update_url,
     Manifest::Location location,
     int creation_flags,
     bool mark_acknowledged) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   CHECK(crx_file::id_util::IdIsValid(id));
 
-  if (Manifest::IsExternalLocation(location)) {
+  // External extensions can be cached because they're the
+  // same across users, but it's necessary to exclude kiosk apps because
+  // the kiosk apps should be constrained in the isolated kiosk session
+  // and should not be shared across.

[not at google - send to devlin, 2015/08/31 18:11:52]

This comment isn't a complete sentence.

[jennyz, 2015/08/31 23:57:25]

Done.

+  if (Manifest::IsExternalLocation(location) &&
+      !extensions::ExtensionsBrowserClient::Get()->IsRunningInForcedAppMode()) {

[not at google - send to devlin, 2015/08/31 18:11:52]

Without this change, does the test you added fail?

[jennyz, 2015/08/31 23:57:25]

Yes, the test will fail since the cache write to a directory under /var which is
not accessible under test environment.

[jennyz, 2015/09/01 16:53:09]

Actually the tests passed now, since I have moved the hard coded cache path to
chromeos PathProvider. So I removed the special case code for kiosk mode here.

     // All extensions that are not user specific can be cached.
     extensions::ExtensionsBrowserClient::Get()->GetExtensionCache()
         ->AllowCaching(id);
   }
 
   const Extension* extension = GetExtensionById(id, true);
   if (extension) {
     // Already installed. Skip this install if the current location has
     // higher priority than |location|.
     Manifest::Location current = extension->location();
@@ skipping 2361 matching lines @@
 }
 
 void ExtensionService::OnProfileDestructionStarted() {
   ExtensionIdSet ids_to_unload = registry_->enabled_extensions().GetIDs();
   for (ExtensionIdSet::iterator it = ids_to_unload.begin();
        it != ids_to_unload.end();
        ++it) {
     UnloadExtension(*it, UnloadedExtensionInfo::REASON_PROFILE_SHUTDOWN);
   }
 }