Drop unused base/tuple.h inclusion

components/content_settings/core/browser/host_content_settings_map.h

 // 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.
 
 // Maps hostnames to custom content settings.  Written on the UI thread and read
 // on any thread.  One instance per profile.
 
 #ifndef COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_HOST_CONTENT_SETTINGS_MAP_H_
 #define COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_HOST_CONTENT_SETTINGS_MAP_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "base/prefs/pref_change_registrar.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_checker.h"
-#include "base/tuple.h"
 #include "components/content_settings/core/browser/content_settings_observer.h"
 #include "components/content_settings/core/browser/content_settings_override_provider.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "components/content_settings/core/common/content_settings_pattern.h"
 #include "components/content_settings/core/common/content_settings_types.h"
 
 class ExtensionService;
 class GURL;
 class PrefService;
 
@@ skipping 322 matching lines @@
   ProviderMap content_settings_providers_;
 
   base::ThreadChecker thread_checker_;
 
   ObserverList<content_settings::Observer> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(HostContentSettingsMap);
 };
 
 #endif  // COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_HOST_CONTENT_SETTINGS_MAP_H_