Add FreeBSD as a supported platform using ninja.

build/landmine_utils.py

 # Copyright 2013 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.
 
 
 import functools
 import logging
 import os
 import shlex
 import sys
@@ skipping 15 matching lines @@
   return memoizer
 
 
 @memoize()
 def IsWindows():
   return sys.platform in ['win32', 'cygwin']
 
 
 @memoize()
 def IsLinux():
-  return sys.platform.startswith('linux')
+  return sys.platform.startswith(('linux', 'freebsd'))
 
 
 @memoize()
 def IsMac():
   return sys.platform == 'darwin'
 
 
 @memoize()
 def gyp_defines():
   """Parses and returns GYP_DEFINES env var as a dictionary."""
@@ skipping 58 matching lines @@
     elif platform() == 'ios':
       return 'xcode'
     elif IsWindows():
       return 'ninja'
     elif IsLinux():
       return 'ninja'
     elif IsMac():
       return 'ninja'
     else:
       assert False, 'Don\'t know what builder we\'re using!'