Cache the numberOfProcessors value on posix and expose it to blink

base/sys_info_internal.h

+// Copyright 2013 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 BASE_SYS_INFO_INTERNAL_H_
+#define BASE_SYS_INFO_INTERNAL_H_
+
+#include "base/basictypes.h"
+
+namespace base {
+
+namespace internal {
+
+template<typename T, T (*F)(void)>
+class LazySysInfoValue {
+ public:
+  LazySysInfoValue()
+      : value_(F()) { }
+
+  ~LazySysInfoValue() { }
+
+  T value() { return value_; }
+
+ private:
+  const T value_;
+
+  DISALLOW_COPY_AND_ASSIGN(LazySysInfoValue);
+};
+
+}  // namespace internal
+
+}  // namespace base
+
+#endif  // BASE_SYS_INFO_INTERNAL_H_