Refine systemInfo.cpu API defintions and provide systemInfo.cpu.get impl for Windows and Linux

chrome/browser/extensions/api/system_info_cpu/cpu_info_provider.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_cpu/cpu_info_provider.h"
+
+#include "base/sys_info.h"
+
+namespace extensions {
+
+using api::experimental_system_info_cpu::CpuInfo;
+
+bool CpuInfoProvider::QueryInfo(CpuInfo* info) {
+  if (info == NULL)
+    return false;
+
+  info->num_of_processors = base::SysInfo::NumberOfProcessors();
+  info->arch_name = base::SysInfo::CPUArchitecture();
+  info->model_name = base::SysInfo::CPUModelName();
+  return true;
+}
+
+bool CpuInfoProvider::StartSampling(const QueryCpuTimeCallback& callback) {
+  // TODO(hongbo): Implement sampling functionality for event router.
+  return false;
+}
+
+bool CpuInfoProvider::StopSampling() {
+  // TODO(hongbo): Implement sampling functionality for event router.
+  return false;
+}
+
+// static
+CpuInfoProvider* CpuInfoProvider::Get() {
+  return CpuInfoProvider::GetInstance<CpuInfoProvider>();
+}
+
+}  // namespace extensions