openbsd and freebsd fixes for base

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 9239aac114fef4380467f08464279de17842c763..47aa3b02886feaf29cf867be198dcc5cffa3f5c9 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1135,13 +1135,15 @@
               '-Wsign-compare',
             ]
           }],
-          [ 'os_posix==1 and OS!="mac" and chromeos==0', {
+          [ 'os_posix==1 and OS!="mac" and OS!="openbsd" and chromeos==0', {
             'cflags': [
               # Don't warn about ignoring the return value from e.g. close().
               # This is off by default in some gccs but on by default in others.
               # Currently this option is not set for Chrome OS build because
               # the current version of gcc (4.3.4) used for building Chrome in
               # Chrome OS chroot doesn't support this option.
+              # OpenBSD does not support this option either, since it's using
+              # gcc 4.2.1, which does not have this flag yet.
               # TODO(mazda): remove the conditional for Chrome OS when gcc
               # version is upgraded.
               '-Wno-unused-result',