Remove X11 and GTK dependencies from host_forwarder

PRESUBMIT.py

 # 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.
 
 """Top-level presubmit script for Chromium.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into gcl.
 """
 
@@ skipping 222 matching lines @@
         r'^base[\\\/]posix[\\\/]eintr_wrapper\.h$',
         r'^ppapi[\\\/]tests[\\\/]test_broker\.cc$',
       ),
     ),
 )
 
 
 _VALID_OS_MACROS = (
     # Please keep sorted.
     'OS_ANDROID',
+    'OS_ANDROID_HOST',
     'OS_BSD',
     'OS_CAT',       # For testing.
     'OS_CHROMEOS',
     'OS_FREEBSD',
     'OS_IOS',
     'OS_LINUX',
     'OS_MACOSX',
     'OS_NACL',
     'OS_OPENBSD',
     'OS_POSIX',
@@ skipping 1202 matching lines @@
     trybots.extend(GetDefaultTryConfigs(['cros_x86']))
 
   # The AOSP bot doesn't build the chrome/ layer, so ignore any changes to it
   # unless they're .gyp(i) files as changes to those files can break the gyp
   # step on that bot.
   if (not all(re.search('^chrome', f) for f in files) or
       any(re.search('\.gypi?$', f) for f in files)):
     trybots.extend(GetDefaultTryConfigs(['android_aosp']))
 
   return trybots