Use precompiled headers for most large projects.

third_party/libjingle/libjingle.gyp

 # Copyright (c) 2011 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': {
     'no_libjingle_logging%': 0,
   },
+  'includes': [
+    '../../build/win_precompile.gypi',
+  ],
   'target_defaults': {
     'defines': [
       'FEATURE_ENABLE_SSL',
       'FEATURE_ENABLE_VOICEMAIL',  # TODO(ncarter): Do we really need this?
       '_USE_32BIT_TIME_T',
       'SAFE_TO_DEFINE_TALK_BASE_LOGGING_MACROS',
       'EXPAT_RELATIVE_PATH',
     ],
     'configurations': {
       'Debug': {
@@ skipping 398 matching lines @@
         'source/talk/session/tunnel/pseudotcpchannel.h',
         'source/talk/session/tunnel/tunnelsessionclient.cc',
         'source/talk/session/tunnel/tunnelsessionclient.h',
       ],
       'dependencies': [
           'libjingle',
       ],
     },
   ],
 }