Fix "unused variable" warnings.

extensions/browser/api/networking_private/networking_private_linux.h

 // Copyright 2014 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.
 
 #ifndef EXTENSIONS_BROWSER_API_NETWORKING_PRIVATE_NETWORKING_PRIVATE_LINUX_H_
 #define EXTENSIONS_BROWSER_API_NETWORKING_PRIVATE_NETWORKING_PRIVATE_LINUX_H_
 
 #include <stdint.h>
 
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/linked_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/threading/thread.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "extensions/browser/api/networking_private/networking_private_delegate.h"
 
-namespace content {
-class BrowserContext;
-}
-
 namespace dbus {
 class Bus;
 class ObjectPath;
 class ObjectProxy;
 class Response;
 };
 
 namespace extensions {
 
 // Linux NetworkingPrivateDelegate implementation.
 class NetworkingPrivateLinux : public NetworkingPrivateDelegate {
  public:
   typedef std::map<base::string16, linked_ptr<base::DictionaryValue>>
       NetworkMap;
 
   typedef std::vector<std::string> GuidList;
 
-  NetworkingPrivateLinux(content::BrowserContext* browser_context,
-                         std::unique_ptr<VerifyDelegate> verify_delegate);
+  explicit NetworkingPrivateLinux(
+      std::unique_ptr<VerifyDelegate> verify_delegate);
 
   // NetworkingPrivateDelegate
   void GetProperties(const std::string& guid,
                      const DictionaryCallback& success_callback,
                      const FailureCallback& failure_callback) override;
   void GetManagedProperties(const std::string& guid,
                             const DictionaryCallback& success_callback,
                             const FailureCallback& failure_callback) override;
   void GetState(const std::string& guid,
                 const DictionaryCallback& success_callback,
@@ skipping 200 matching lines @@
   void OnNetworksChangedEventTask(std::unique_ptr<GuidList> guid_list);
 
   void GetCachedNetworkProperties(const std::string& guid,
                                   base::DictionaryValue* properties,
                                   std::string* error);
 
   void OnNetworksChangedEventOnUIThread(const GuidList& network_guids);
 
   void OnNetworkListChangedEventOnUIThread(const GuidList& network_guids);
 
-  // Browser context.
-  content::BrowserContext* browser_context_;
   // Thread used for DBus actions.
   base::Thread dbus_thread_;
   // DBus instance. Only access on |dbus_thread_|.
   scoped_refptr<dbus::Bus> dbus_;
   // Task runner used by the |dbus_| object.
   scoped_refptr<base::SequencedTaskRunner> dbus_task_runner_;
   // This is owned by |dbus_| object. Only access on |dbus_thread_|.
   dbus::ObjectProxy* network_manager_proxy_;
   // Holds the current mapping of known networks. Only access on |dbus_thread_|.
   std::unique_ptr<NetworkMap> network_map_;
   // Observers to Network Events.
   base::ObserverList<NetworkingPrivateDelegateObserver>
       network_events_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkingPrivateLinux);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_NETWORKING_PRIVATE_NETWORKING_PRIVATE_LINUX_H_