cr: Add support for GN build file generation

tools/cr/cr/actions/gyp.py

 # Copyright 2013 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.
 
 """A module to add gyp support to cr."""
 
 import cr
 import os
 
 GYP_DEFINE_PREFIX = 'GYP_DEF_'
 
 class GypPrepareOut(cr.PrepareOut):
   """A prepare action that runs gyp whenever you select an output directory."""
 
-  ENABLED = cr.Config.From(
+  ACTIVE = cr.Config.From(
       GYP_GENERATORS='ninja',
       GYP_GENERATOR_FLAGS='output_dir={CR_OUT_BASE} config={CR_BUILDTYPE}',
       GYP_DEF_target_arch='{CR_ENVSETUP_ARCH}',
   )
 
   def UpdateContext(self):
     # Collapse GYP_DEFINES from all GYP_DEF prefixes
     gyp_defines = cr.context.Find('GYP_DEFINES') or ''
     for key, value in cr.context.exported.items():
       if key.startswith(GYP_DEFINE_PREFIX):
         gyp_defines += ' %s=%s' % (key[len(GYP_DEFINE_PREFIX):], value)
     cr.context['GYP_DEFINES'] = gyp_defines.strip()
     if cr.context.verbose >= 1:
       print cr.context.Substitute('GYP_DEFINES = {GYP_DEFINES}')
 
   def Prepare(self):
     if cr.context.verbose >= 1:
       print cr.context.Substitute('Invoking gyp with {GYP_GENERATOR_FLAGS}')
 
     cr.Host.Execute(
         '{CR_SRC}/build/gyp_chromium',
         '--depth={CR_SRC}',
         '--check'
     )