Use precompiled headers for most large projects.

third_party/libphonenumber/libphonenumber.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.
 
 {
   'target_defaults': {
     'include_dirs': [
       '../..',  # add it first, so src/base headers are used instead of the ones
                 # brought with the library as cc files would be taken from the
                 # main chrome tree as well.
       'cpp/src',
       # The libphonenumber source (and test code) expects the
       # generated protocol headers to be available with no include
       # path, e.g. #include "foo.pb.h".
       '<(SHARED_INTERMEDIATE_DIR)/protoc_out/third_party/libphonenumber',
     ],
     'defines': [
       'USE_HASH_MAP=1',
       'USE_GOOGLE_BASE=1',
     ],
   },
+  'includes': [
+    '../../build/win_precompile.gypi',
+  ],
   'targets': [{
     'target_name': 'libphonenumber',
     'type': 'static_library',
     'dependencies': [
       '../icu/icu.gyp:icui18n',
       '../icu/icu.gyp:icuuc',
       '../../base/base.gyp:base',
       '../../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
     ],
     'sources': [
@@ skipping 55 matching lines @@
     ],
     'conditions': [
       ['OS=="win"', {
         'action': [
           '/wo4309',
         ],
       }],
     ],
   }]
 }