Remove redundant c_str() calls.

chrome/browser/extensions/api/preference/preference_helpers.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/preference/preference_helpers.h"
 
 #include <utility>
 
 #include "base/json/json_writer.h"
 #include "base/values.h"
@@ skipping 44 matching lines @@
 const char* GetLevelOfControl(
     Profile* profile,
     const std::string& extension_id,
     const std::string& browser_pref,
     bool incognito) {
   PrefService* prefs = incognito ? profile->GetOffTheRecordPrefs()
                                  : profile->GetPrefs();
   bool from_incognito = false;
   bool* from_incognito_ptr = incognito ? &from_incognito : NULL;
   const PrefService::Preference* pref =
-      prefs->FindPreference(browser_pref.c_str());
+      prefs->FindPreference(browser_pref);
   CHECK(pref);
 
   if (!pref->IsExtensionModifiable())
     return kNotControllable;
 
   if (PreferenceAPI::Get(profile)->DoesExtensionControlPref(
           extension_id,
           browser_pref,
           from_incognito_ptr)) {
     return kControlledByThisExtension;
@@ skipping 55 matching lines @@
       std::unique_ptr<Event> event(
           new Event(histogram_value, event_name, std::move(args_copy)));
       event->restrict_to_browser_context = restrict_to_profile;
       router->DispatchEventToExtension(extension->id(), std::move(event));
     }
   }
 }
 
 }  // namespace preference_helpers
 }  // namespace extensions