Tabs API is usable without tabs permission.

chrome/common/extensions/permissions/permission_set_unittest.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 "base/command_line.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/chrome_paths.h"
@@ skipping 629 matching lines @@
     { "devtools",       true },
     { "extension",      true },
     { "i18n",           true },
     { "pageAction",     true },
     { "pageActions",    true },
     { "test",           true },
     // Some negative tests.
     { "bookmarks",      false },
     { "cookies",        false },
     { "history",        false },
-    { "tabs.onUpdated", false },
     // Make sure we find the module name after stripping '.' and '/'.
     { "browserAction/abcd/onClick",  true },
     { "browserAction.abcd.onClick",  true },
     // Test Tabs functions.
     { "tabs.create",      true},
     { "tabs.update",      true},
-    { "tabs.getSelected", false},
+    { "tabs.getSelected", true},
+    { "tabs.onUpdated",   true },
   };
 
   scoped_refptr<PermissionSet> empty = new PermissionSet();
   for (size_t i = 0; i < ARRAYSIZE_UNSAFE(kTests); ++i) {
     EXPECT_EQ(kTests[i].expect_success,
-              empty->HasAccessToFunction(kTests[i].permission_name));
+              empty->HasAccessToFunction(kTests[i].permission_name))
+                  << "Permission being tested: " << kTests[i].permission_name;
   }
 }
 
 // Tests the default permissions (empty API permission set).
 TEST(PermissionsTest, DefaultAnyAPIAccess) {
   const struct {
     const char* api_name;
     bool expect_success;
   } kTests[] = {
     // Negative test.
@@ skipping 473 matching lines @@
   apis.insert(APIPermission::kWebRequest);
   apis.insert(APIPermission::kFileBrowserHandler);
   EXPECT_EQ(2U, apis.size());
 
   scoped_refptr<PermissionSet> perm_set;
   perm_set = new PermissionSet(apis, empty_extent, empty_extent);
   EXPECT_EQ(4U, perm_set->apis().size());
 }
 
 }  // namespace extensions