Remove redundant c_str() calls.

chrome/browser/extensions/api/autotest_private/autotest_private_api.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/autotest_private/autotest_private_api.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/lazy_instance.h"
@@ skipping 44 matching lines @@
 
   return permissions;
 }
 
 base::ListValue* GetAPIPermissions(const Extension* ext) {
   base::ListValue* permissions = new base::ListValue;
   std::set<std::string> perm_list =
       ext->permissions_data()->active_permissions().GetAPIsAsStrings();
   for (std::set<std::string>::const_iterator perm = perm_list.begin();
        perm != perm_list.end(); ++perm) {
-    permissions->AppendString(perm->c_str());
+    permissions->AppendString(*perm);
   }
   return permissions;
 }
 
 bool IsTestMode(content::BrowserContext* context) {
   return AutotestPrivateAPI::GetFactoryInstance()->Get(context)->test_mode();
 }
 
 }  // namespace
 
@@ skipping 318 matching lines @@
   return new AutotestPrivateAPI();
 }
 
 AutotestPrivateAPI::AutotestPrivateAPI() : test_mode_(false) {
 }
 
 AutotestPrivateAPI::~AutotestPrivateAPI() {
 }
 
 }  // namespace extensions