openbsd and freebsd fixes for base

base/sys_info_openbsd.cc

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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 "base/sys_info.h"
 
 #include <sys/param.h>
 #include <sys/sysctl.h>
 
 #include "base/logging.h"
 
 namespace base {
 
 int SysInfo::NumberOfProcessors() {
   int mib[] = { CTL_HW, HW_NCPU };
   int ncpu;
   size_t size = sizeof(ncpu);
   if (sysctl(mib, 2, &ncpu, &size, NULL, 0) == -1) {
     NOTREACHED();
     return 1;
   }
   return ncpu;
 }
 
+int64 SysInfo::AmountOfPhysicalMemory() {
+  long pages = sysconf(_SC_PHYS_PAGES);
+  long page_size = sysconf(_SC_PAGESIZE);
+  if (pages == -1 || page_size == -1) {
+    NOTREACHED();
+    return 0;
+  }
+
+  return static_cast<int64>(pages) * page_size;
+}
+
 }  // namespace base