Enable compiling with automatically-downloaded VS toolchain on Windows bots

gyp_skia

 #!/usr/bin/python
 
 # Copyright 2011 The Android Open Source Project
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script is a wrapper which invokes gyp with the correct --depth argument,
 # and supports the automatic regeneration of build files if all.gyp is
 # changed (Linux-only).
@@ skipping 75 matching lines @@
       default_gyp_generators = 'ninja,xcode'
     elif sys.platform.startswith('win'):
       default_gyp_generators = 'ninja,msvs-ninja'
     elif sys.platform.startswith('cygwin'):
       default_gyp_generators = 'ninja,msvs-ninja'
     else:
       default_gyp_generators = 'ninja'
     os.environ[ENVVAR_GYP_GENERATORS] = default_gyp_generators
   print '%s is "%s"' % (ENVVAR_GYP_GENERATORS, os.getenv(ENVVAR_GYP_GENERATORS))
 
+  if os.getenv('CHROME_HEADLESS', '0') == '1':
+    if sys.platform.startswith('win') or sys.platform.startswith('cygwin'):
+      chrome_path = os.getenv('CHROME_PATH')
+      os.chdir(chrome_path)
+      sys.path.append(os.path.join(chrome_path, 'build'))
+      sys.path.append(os.path.join(chrome_path, 'tools'))
+      import vs_toolchain
+      vs_toolchain.Update()
+      vs_toolchain.GetToolchainDir()
+
   # Set CWD to the directory containing this script.
   # This allows us to launch it from other directories, in spite of gyp's
   # finickyness about the current working directory.
   # See http://b.corp.google.com/issue?id=5019517 ('Linux make build
   # (from out dir) no longer runs skia_gyp correctly')
   os.chdir(os.path.abspath(script_dir))
 
   # This could give false positives since it doesn't actually do real option
   # parsing.  Oh well.
   gyp_file_specified = False
@@ skipping 35 matching lines @@
 
   print 'Updating projects from gyp files...'
   sys.stdout.flush()
 
   if '--dry-run' in args:
     args.remove('--dry-run')
     print gyp_source_dir, ' '.join(args)
   else:
     # Off we go...
     sys.exit(gyp.main(args))