Add a generic template for system info provider

chrome/browser/extensions/api/system_info_cpu/system_info_cpu_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_SYSTEM_INFO_CPU_SYSTEM_INFO_CPU_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_SYSTEM_INFO_CPU_SYSTEM_INFO_CPU_API_H_
 
 #include "chrome/browser/extensions/extension_function.h"
+#include "chrome/common/extensions/api/experimental_system_info_cpu.h"
 
 namespace extensions {
 
-class CpuInfoProvider;
-
 class SystemInfoCpuGetFunction : public AsyncExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.systemInfo.cpu.get");
   SystemInfoCpuGetFunction();
 
  private:
   virtual ~SystemInfoCpuGetFunction();
   virtual bool RunImpl() OVERRIDE;
-  void WorkOnFileThread();
-  void RespondOnUIThread(bool success);
-  void GetCpuInfoOnFileThread();
-
-  // The CpuInfoProvider instance, lives on FILE thread.
-  CpuInfoProvider* provider_;
+  void OnGetCpuInfoCompleted(
+      const api::experimental_system_info_cpu::CpuInfo& info, bool success);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_SYSTEM_INFO_CPU_SYSTEM_INFO_CPU_API_H_