[Cronet] Use gn desc deps to find third_party licenses.

components/cronet/tools/cr_cronet.py

 #!/usr/bin/python
 # Copyright 2014 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.
 
 """
 cr_cronet.py - cr - like helper tool for cronet developers
 """
 
 import argparse
@@ skipping 59 matching lines @@
                       help='use release configuration')
 
   options, extra_options_list = parser.parse_known_args()
   print options
   print extra_options_list
 
   is_os = (sys.platform == 'darwin')
   if is_os:
     target_os = 'ios'
     test_target = 'cronet_test'
+    gn_args = 'target_cpu = "x64" '
     out_dir_suffix = '-iphonesimulator'
     if options.iphoneos:
+      gn_args = 'target_cpu = "arm64" '
       out_dir_suffix = '-iphoneos'
   else:
     target_os = 'android'
     test_target = 'cronet_test_instrumentation_apk'
+    gn_args = 'use_errorprone_java_compiler=true '
     out_dir_suffix = ''
 
   gyp_defines = 'GYP_DEFINES="OS=' + target_os + ' enable_websockets=0 '+ \
       'disable_file_support=1 disable_ftp_support=1 '+ \
       'enable_errorprone=1 use_platform_icu_alternatives=1 ' + \
       'disable_brotli_filter=1"'
-  gn_args = 'target_os="' + target_os + '" enable_websockets=false '+ \
+  gn_args += 'target_os="' + target_os + '" enable_websockets=false '+ \
       'disable_file_support=true disable_ftp_support=true '+ \
-      'use_errorprone_java_compiler=true use_platform_icu_alternatives=true '+ \
+      'use_platform_icu_alternatives=true '+ \
       'disable_brotli_filter=true'
 
   extra_options = ' '.join(extra_options_list)
   if options.release:
     out_dir = 'out/Release' + out_dir_suffix

[brettw, 2016/05/03 22:13:03]

We should pick a different directory name to avoid clobbering the user's build.
This is actually really bad for several reasons:

  - Currently you can have GYP and GN side-by-side. If you run GN build, this
will corrupt your GYP build to the point you need to delete the directory to
erase all sources of flakiness.

  - If the user is using GN and put their build in one of these locations, this
code will delete their build configuration and replace it with the args
specified here.

We should be making a temporary directory that doesn't exist before.

[mef, 2016/05/11 15:57:27]

Done.

     release_arg = ' --release'
     gn_args += ' is_debug=false '
   else:
     out_dir = 'out/Debug' + out_dir_suffix
     release_arg = ''
 
   if options.out_dir:
     out_dir = options.out_dir
 
   if (options.command=='gyp'):
@@ skipping 25 matching lines @@
       return test_ios(out_dir, extra_options)
     if (options.command=='build-test'):
       return build(out_dir, test_target) or test_ios(out_dir, extra_options)
 
   parser.print_help()
   return 1
 
 
 if __name__ == '__main__':
   sys.exit(main())