Fix free memory calculation.

base/sys_info_openbsd.cc

 // 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 <stddef.h>
 #include <stdint.h>
 #include <sys/param.h>
 #include <sys/shm.h>
@@ skipping 30 matching lines @@
   return ncpu;
 }
 
 // static
 int64_t SysInfo::AmountOfPhysicalMemory() {
   return AmountOfMemory(_SC_PHYS_PAGES);
 }
 
 // static
 int64_t SysInfo::AmountOfAvailablePhysicalMemory() {
+  // We should add inactive file-backed memory also but there is no such
+  // information from OpenBSD unfortunately.
   return AmountOfMemory(_SC_AVPHYS_PAGES);
 }
 
 // static
 uint64_t SysInfo::MaxSharedMemorySize() {
   int mib[] = { CTL_KERN, KERN_SHMINFO, KERN_SHMINFO_SHMMAX };
   size_t limit;
   size_t size = sizeof(limit);
   if (sysctl(mib, arraysize(mib), &limit, &size, NULL, 0) < 0) {
     NOTREACHED();
     return 0;
   }
   return static_cast<uint64_t>(limit);
 }
 
 // static
 std::string SysInfo::CPUModelName() {
   int mib[] = { CTL_HW, HW_MODEL };
   char name[256];
   size_t len = arraysize(name);
   if (sysctl(mib, arraysize(mib), name, &len, NULL, 0) < 0) {
     NOTREACHED();
     return std::string();
   }
   return name;
 }
 
 }  // namespace base