[SystemInfo API] Finish TODOs in SystemInfoProvider

chrome/browser/extensions/api/system_info_display/display_info_provider_mac.cc

 // 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.
 
 #include "chrome/browser/extensions/api/system_info_display/display_info_provider.h"
 
 namespace extensions {
 
 void DisplayInfoProvider::RequestInfo(const RequestInfoCallback& callback) {
   // Redirect the request to a worker pool thread.
   StartQueryInfo(callback);
 }
 
 void DisplayInfoProvider::SetInfo(
     const std::string& display_id,
     const api::system_info_display::DisplayProperties& info,
     const SetInfoCallback& callback) {
   base::MessageLoopProxy::current()->PostTask(
       FROM_HERE,
       base::Bind(callback, false, "Not implemented"));
 }
 
 // TODO(hongbo): implement display info querying on Mac OS X.
-bool DisplayInfoProvider::QueryInfo(DisplayInfo* info) {
+bool DisplayInfoProvider::QueryInfo() {
   return false;
 }
 
 }  // namespace extensions