Delete some unused code found by -Wunused-function

chrome/browser/extensions/api/webstore_private/webstore_private_api.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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_WEBSTORE_PRIVATE_WEBSTORE_PRIVATE_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_WEBSTORE_PRIVATE_WEBSTORE_PRIVATE_API_H_
 
 #include <string>
 
 #include "chrome/browser/extensions/bundle_installer.h"
@@ skipping 10 matching lines @@
 class ProfileSyncService;
 
 namespace content {
 class GpuDataManager;
 }
 
 namespace extensions {
 
 class WebstorePrivateApi {
  public:
-  // Allows you to set the ProfileSyncService the function will use for
-  // testing purposes.
-  static void SetTestingProfileSyncService(ProfileSyncService* service);
-
   // Allows you to override the WebstoreInstaller delegate for testing.
   static void SetWebstoreInstallerDelegateForTesting(
       WebstoreInstaller::Delegate* delegate);
 
   // Gets the pending approval for the |extension_id| in |profile|. Pending
   // approvals are held between the calls to beginInstallWithManifest and
   // completeInstall. This should only be used for testing.
   static scoped_ptr<WebstoreInstaller::Approval> PopApprovalForTesting(
       Profile* profile, const std::string& extension_id);
 };
@@ skipping 170 matching lines @@
 
  private:
   void CreateResult(bool webgl_allowed);
 
   scoped_refptr<GPUFeatureChecker> feature_checker_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_WEBSTORE_PRIVATE_WEBSTORE_PRIVATE_API_H_