Packaged apps can be granted file:/// access too.

chrome/browser/renderer_host/chrome_render_view_host_observer.cc

 // Copyright (c) 2011 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/renderer_host/chrome_render_view_host_observer.h"
 
 #include "base/command_line.h"
 #include "chrome/browser/dom_operation_notification_details.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/net/predictor.h"
@@ skipping 96 matching lines @@
     profile_->GetExtensionService()->SetInstalledAppForRenderer(
         process->GetID(), extension);
   }
 
   // Some extensions use chrome:// URLs.
   Extension::Type type = extension->GetType();
   if (type == Extension::TYPE_EXTENSION ||
       type == Extension::TYPE_PACKAGED_APP) {
     ChildProcessSecurityPolicy::GetInstance()->GrantScheme(
         process->GetID(), chrome::kChromeUIScheme);
-  }
 
-  if (type == Extension::TYPE_EXTENSION &&
-      profile_->GetExtensionService()->extension_prefs()->AllowFileAccess(
+    if (profile_->GetExtensionService()->extension_prefs()->AllowFileAccess(
           extension->id())) {
-    ChildProcessSecurityPolicy::GetInstance()->GrantScheme(
-        process->GetID(), chrome::kFileScheme);
+      ChildProcessSecurityPolicy::GetInstance()->GrantScheme(
+          process->GetID(), chrome::kFileScheme);
+    }
   }
 
   if (type == Extension::TYPE_EXTENSION ||
       type == Extension::TYPE_USER_SCRIPT ||
       type == Extension::TYPE_PACKAGED_APP ||
       (type == Extension::TYPE_HOSTED_APP &&
        extension->location() == Extension::COMPONENT)) {
     Send(new ExtensionMsg_ActivateExtension(extension->id()));
   }
 }
@@ skipping 40 matching lines @@
       content::Source<RenderViewHost>(render_view_host()),
       content::Details<DomOperationNotificationDetails>(&details));
 }
 
 void ChromeRenderViewHostObserver::OnFocusedEditableNodeTouched() {
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_FOCUSED_EDITABLE_NODE_TOUCHED,
       content::Source<RenderViewHost>(render_view_host()),
       content::NotificationService::NoDetails());
 }