Tabs API is usable without tabs permission.

chrome/test/data/extensions/api_test/permissions/disabled/background.js

 // 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.
 
-// All of the calls to chrome.* functions should fail, since this extension
-// has requested no permissions.
+// All of the calls to chrome.* functions should fail, with the exception of
+// chrome.tabs.*, since this extension has requested no permissions.
 
 chrome.test.runTests([
   function history() {
     try {
       var query = { 'text': '', 'maxResults': 1 };
       chrome.history.search(query, function(results) {
         chrome.test.fail();
       });
     } catch (e) {
       chrome.test.succeed();
     }
   },
 
   function bookmarks() {
     try {
       chrome.bookmarks.get("1", function(results) {
         chrome.test.fail();
       });
     } catch (e) {
       chrome.test.succeed();
     }
   },
 
+  // Tabs functionality should be enabled even if the tabs permissions are not
+  // present.
   function tabs() {
     try {
-      chrome.tabs.getSelected(null, function(results) {
-        chrome.test.fail();
+      chrome.tabs.create({'url': '1'}, function(tab) {
+        // Tabs strip sensitive data without permissions.
+        //chrome.test.assertFalse(tab.url)
+        chrome.test.assertEq('', tab.url)
+        chrome.test.succeed();
       });
     } catch (e) {
-      chrome.test.succeed();
+      chrome.test.fail();
     }
   },
 
   function idle() {
     try {
       chrome.idle.queryState(60, function(state) {
         chrome.test.fail();
       });
     } catch (e) {
       chrome.test.succeed();
     }
   }
 ]);