Fix "unused variable" warnings.

components/signin/core/browser/signin_tracker.cc

 // 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.
 
 #include "components/signin/core/browser/signin_tracker.h"
 
 #include "components/signin/core/browser/gaia_cookie_manager_service.h"
 #include "components/signin/core/browser/profile_oauth2_token_service.h"
-#include "components/signin/core/browser/signin_client.h"
 #include "google_apis/gaia/gaia_constants.h"
 
 SigninTracker::SigninTracker(ProfileOAuth2TokenService* token_service,
                              SigninManagerBase* signin_manager,
                              GaiaCookieManagerService* cookie_manager_service,
-                             SigninClient* client,
                              Observer* observer)
     : token_service_(token_service),
       signin_manager_(signin_manager),
       cookie_manager_service_(cookie_manager_service),
-      client_(client),
       observer_(observer) {
   Initialize();
 }
 
 SigninTracker::~SigninTracker() {
   signin_manager_->RemoveObserver(this);
   token_service_->RemoveObserver(this);
   cookie_manager_service_->RemoveObserver(this);
 }
 
@@ skipping 17 matching lines @@
 
 void SigninTracker::OnRefreshTokenRevoked(const std::string& account_id) {
   NOTREACHED();
 }
 
 void SigninTracker::OnAddAccountToCookieCompleted(
     const std::string& account_id,
     const GoogleServiceAuthError& error) {
   observer_->AccountAddedToCookie(error);
 }