posix: split linux-specific bits out of sys_info_posix

base/base.gyp

Index: base/base.gyp
diff --git a/base/base.gyp b/base/base.gyp
index e7eda0916d09e7a2fc751cc821e62eed0e2e06f3..5ba7d4b310c7fa822371a0b2f9a956bde4427d02 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -297,7 +297,10 @@
         'string_util_win.h',
         'sys_info.h',
         'sys_info_chromeos.cc',
+        'sys_info_freebsd.cc',
+        'sys_info_linux.cc',
         'sys_info_mac.cc',
+        'sys_info_openbsd.cc',
         'sys_info_posix.cc',
         'sys_info_win.cc',
         'sys_string_conversions.h',
@@ -465,6 +468,16 @@
             ],
           },
         ],
+        # For now, just test the *BSD platforms enough to exclude them.
+        # Subsequent changes will include them further.
+        [ 'OS != "freebsd"', {
+            'sources/': [ ['exclude', '_freebsd\\.cc$'] ],
+          },
+        ],
+        [ 'OS != "openbsd"', {
+            'sources/': [ ['exclude', '_openbsd\\.cc$'] ],
+          },
+        ],
         [ 'GENERATOR == "quentin"', {
             # Quentin builds don't have a recent enough glibc to include the
             # inotify headers