Continue with the FreeBSD port - this version builds and links, though...

sdch/sdch.gyp

 # Copyright (c) 2009 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     '../build/common.gypi',
@@ skipping 39 matching lines @@
       ],
       'include_dirs': [
         'open-vcdiff/src',
       ],
       'direct_dependent_settings': {
         'include_dirs': [
           'open-vcdiff/src',
         ],
       },
       'conditions': [
-        [ 'OS == "linux"', { 'include_dirs': [ 'linux' ] } ],
+        [ 'OS == "linux" or OS == "freebsd"', { 'include_dirs': [ 'linux' ] } ],
         [ 'OS == "mac"', { 'include_dirs': [ 'mac' ] } ],
         [ 'OS == "win"', { 'include_dirs': [ 'open-vcdiff/vsprojects' ] } ],
       ],
     },
   ],
 }