Tabs API is usable without tabs permission.

chrome/browser/extensions/api/messaging/message_service.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/api/messaging/message_service.h"
 
 #include "base/atomic_sequence_num.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/json/json_writer.h"
@@ skipping 201 matching lines @@
   // which depends on whether the extension uses spanning or split mode.
   MessagePort receiver(GetExtensionProcess(profile, target_extension_id),
                        MSG_ROUTING_CONTROL,
                        target_extension_id);
   WebContents* source_contents = tab_util::GetWebContentsByID(
       source_process_id, source_routing_id);
 
   // Include info about the opener's tab (if it was a tab).
   std::string tab_json = "null";
   if (source_contents) {
-    scoped_ptr<DictionaryValue> tab_value(
-        ExtensionTabUtil::CreateTabValue(source_contents));
+    scoped_ptr<DictionaryValue> tab_value(ExtensionTabUtil::CreateTabValue(
+            source_contents,
+            profile->GetExtensionService()->extensions()->GetByID(
+                source_extension_id)));
     base::JSONWriter::Write(tab_value.get(), &tab_json);
   }
 
   OpenChannelParams params(source, tab_json, receiver, receiver_port_id,
                            source_extension_id, target_extension_id,
                            channel_name);
 
   // The target might be a lazy background page. In that case, we have to check
   // if it is loaded and ready, and if not, queue up the task and load the
   // page.
@@ skipping 30 matching lines @@
                          GET_OPPOSITE_PORT_ID(receiver_port_id), true);
     return;
   }
 
   WebContents* source_contents = tab_util::GetWebContentsByID(
       source_process_id, source_routing_id);
 
   // Include info about the opener's tab (if it was a tab).
   std::string tab_json = "null";
   if (source_contents) {
-    scoped_ptr<DictionaryValue> tab_value(
-        ExtensionTabUtil::CreateTabValue(source_contents));
+    scoped_ptr<DictionaryValue> tab_value(ExtensionTabUtil::CreateTabValue(
+            source_contents,
+            profile->GetExtensionService()->extensions()->GetByID(
+                extension_id)));
     base::JSONWriter::Write(tab_value.get(), &tab_json);
   }
 
   OpenChannelParams params(source, tab_json, receiver, receiver_port_id,
                            extension_id, extension_id, channel_name);
   OpenChannelImpl(params);
 }
 
 bool MessageService::OpenChannelImpl(const OpenChannelParams& params) {
   if (!params.source)
@@ skipping 176 matching lines @@
   if (!params.source)
     return;
 
   params.receiver = MessagePort(host->render_process_host(),
                                 MSG_ROUTING_CONTROL,
                                 params.target_extension_id);
   OpenChannelImpl(params);
 }
 
 }  // namespace extensions