GN: aix port along with linux_s390x, linux_ppc64 and linux_ppc64le support.

base/sys_info.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 BASE_SYS_INFO_H_
 #define BASE_SYS_INFO_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 142 matching lines @@
 
   // Returns true if this is a low-end device.
   // Low-end device refers to devices having less than 512M memory in the
   // current implementation.
   static bool IsLowEndDevice();
 
  private:
   FRIEND_TEST_ALL_PREFIXES(SysInfoTest, AmountOfAvailablePhysicalMemory);
   FRIEND_TEST_ALL_PREFIXES(debug::SystemMetricsTest, ParseMeminfo);
 
-#if defined(OS_LINUX) || defined(OS_ANDROID)
+#if defined(OS_LINUX) || defined(OS_ANDROID) || defined(OS_AIX)
   static int64_t AmountOfAvailablePhysicalMemory(
       const SystemMemoryInfoKB& meminfo);
 #endif
 };
 
 }  // namespace base
 
 #endif  // BASE_SYS_INFO_H_