Tabs API is usable without tabs permission.

chrome/browser/extensions/execute_script_apitest.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/extension_apitest.h"
 #include "net/base/mock_host_resolver.h"
 
 class ExecuteScriptApiTest : public ExtensionApiTest {
  protected:
   void SetupDelayedHostResolver() {
@@ skipping 18 matching lines @@
   ASSERT_TRUE(RunExtensionTest("executescript/in_frame")) << message_;
 }
 
 IN_PROC_BROWSER_TEST_F(ExecuteScriptApiTest, ExecuteScriptPermissions) {
   SetupDelayedHostResolver();
   ASSERT_TRUE(StartTestServer());
   ASSERT_TRUE(RunExtensionTest("executescript/permissions")) << message_;
 }
 
 // If failing, mark disabled and update http://crbug.com/84760.
-IN_PROC_BROWSER_TEST_F(ExecuteScriptApiTest,
-                       ExecuteScriptFileAfterClose) {
+IN_PROC_BROWSER_TEST_F(ExecuteScriptApiTest, ExecuteScriptFileAfterClose) {
   host_resolver()->AddRule("b.com", "127.0.0.1");
   ASSERT_TRUE(StartTestServer());
   ASSERT_TRUE(RunExtensionTest("executescript/file_after_close")) << message_;
 }
 
 // If crashing, mark disabled and update http://crbug.com/67774.
 IN_PROC_BROWSER_TEST_F(ExecuteScriptApiTest, ExecuteScriptFragmentNavigation) {
   ASSERT_TRUE(StartTestServer());
   const char* extension_name = "executescript/fragment";
   ASSERT_TRUE(RunExtensionTest(extension_name)) << message_;
@@ skipping 26 matching lines @@
   SetupDelayedHostResolver();
   ASSERT_TRUE(StartTestServer());
   ASSERT_TRUE(RunExtensionTest("executescript/run_at")) << message_;
 }
 
 IN_PROC_BROWSER_TEST_F(ExecuteScriptApiTest, ExecuteScriptCallback) {
   SetupDelayedHostResolver();
   ASSERT_TRUE(StartTestServer());
   ASSERT_TRUE(RunExtensionTest("executescript/callback")) << message_;
 }