Fix "unused variable" warnings.

extensions/renderer/request_sender.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_RENDERER_REQUEST_SENDER_H_
 #define EXTENSIONS_RENDERER_REQUEST_SENDER_H_
 
 #include <map>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/linked_ptr.h"
 #include "v8/include/v8.h"
 
 namespace base {
 class ListValue;
 }
 
 namespace extensions {
-class Dispatcher;
 class ScriptContext;
 
 struct PendingRequest;
 
 // Responsible for sending requests for named extension API functions to the
 // extension host and routing the responses back to the caller.
 class RequestSender {
  public:
   // Source represents a user of RequestSender. Every request is associated with
   // a Source object, which will be notified when the corresponding response
@@ skipping 19 matching lines @@
     ~ScopedTabID();
 
    private:
     RequestSender* const request_sender_;
     const int tab_id_;
     const int previous_tab_id_;
 
     DISALLOW_COPY_AND_ASSIGN(ScopedTabID);
   };
 
-  explicit RequestSender(Dispatcher* dispatcher);
+  RequestSender();
   ~RequestSender();
 
   // In order to avoid collision, all |request_id|s passed into StartRequest()
   // should be generated by this method.
   int GetNextRequestId() const;
 
   // Makes a call to the API function |name| that is to be handled by the
   // extension host. The response to this request will be received in
   // HandleResponse().
   // TODO(koz): Remove |request_id| and generate that internally.
@@ skipping 16 matching lines @@
   // TODO(kalman): Do this in a generic/safe way.
   void InvalidateSource(Source* source);
 
  private:
   friend class ScopedTabID;
   typedef std::map<int, linked_ptr<PendingRequest> > PendingRequestMap;
 
   void InsertRequest(int request_id, PendingRequest* pending_request);
   linked_ptr<PendingRequest> RemoveRequest(int request_id);
 
-  Dispatcher* dispatcher_;
   PendingRequestMap pending_requests_;
 
   int source_tab_id_;  // Id of the tab sending the request, or -1 if no tab.
 
   DISALLOW_COPY_AND_ASSIGN(RequestSender);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_REQUEST_SENDER_H_