Remove all uncessary files for build_nexe.py on Windows.

base/base.gypi

 # 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.
 
 {
   'target_defaults': {
     'variables': {
       'base_target': 0,
     },
     'target_conditions': [
@@ skipping 637 matching lines @@
               ['exclude', '^process_linux\\.cc$'],
               ['exclude', '^process_util_linux\\.cc$'],
               ['exclude', '^sys_info_linux\\.cc$'],
             ],
           }],
           ['<(chromeos)!=1 or >(nacl_untrusted_build)==1', {
             'sources/': [
               ['exclude', '^chromeos/'],
             ],
           }],
+          # Remove all unnecessary files for build_nexe.py to avoid exceeding
+          # command-line-string limitation when building NaCl on Windows.
+          ['OS == "win" and >(nacl_untrusted_build)==1', {
+              'sources/': [ ['exclude', '\\.h$'] ],
+          }],
         ],
       }],
     ],
   },
 }