Adding fixed guids to some modules to facilitate incremental switch to gyp.

third_party/libpng/libpng.gyp

 # Copyright (c) 2009 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.
 
 {
   'includes': [
     '../../build/common.gypi',
   ],
   'targets': [
     {
       'target_name': 'libpng',
       'type': 'static_library',
       'dependencies': [
         '../zlib/zlib.gyp:zlib',
       ],
       'defines': [
         'CHROME_PNG_WRITE_SUPPORT',
         'PNG_USER_CONFIG',
       ],
+      'msvs_guid': 'C564F145-9172-42C3-BFCB-6014CA97DBCD',
       'sources': [
         'png.c',
         'png.h',
         'pngconf.h',
         'pngerror.c',
         'pnggccrd.c',
         'pngget.c',
         'pngmem.c',
         'pngpread.c',
         'pngread.c',
@@ skipping 20 matching lines @@
       },
       'export_dependent_settings': [
         '../zlib/zlib.gyp:zlib',
       ],
       'conditions': [
         ['OS!="win"', {'product_name': 'png'}],
       ],
     },
   ],
 }