Add widevine and extensions resources to GN build.

third_party/widevine/cdm/widevine_cdm.gyp

 # Copyright (c) 2012 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.
 
 {
   'variables': {
     'widevine_cdm_version_h_file%': 'widevine_cdm_version.h',
     'widevine_cdm_binary_files%': [],
     'conditions': [
       [ 'branding == "Chrome"', {
@@ skipping 32 matching lines @@
       [ 'OS == "android"', {
         'widevine_cdm_version_h_file%':
             'android/widevine_cdm_version.h',
       }],
     ],
   },
   # Always provide a target, so we can put the logic about whether there's
   # anything to be done in this file (instead of a higher-level .gyp file).
   'targets': [
     {
+      # GN version: //third_party/widevine/cdm:adapter
       'target_name': 'widevinecdmadapter',
       'type': 'none',
       'conditions': [
         [ 'branding == "Chrome" and enable_pepper_cdms==1', {
           'dependencies': [
             '<(DEPTH)/ppapi/ppapi.gyp:ppapi_cpp',
             '<(DEPTH)/media/media_cdm_adapter.gyp:cdmadapter',
             'widevine_cdm_version_h',
             'widevine_cdm_binaries',
           ],
@@ skipping 14 matching lines @@
               'libraries': [
                 # Copied by widevine_cdm_binaries.
                 '<(PRODUCT_DIR)/libwidevinecdm.dylib',
               ],
             }],
           ],
         }],
       ],
     },
     {
+      # GN version: //third_party/widevine/cdm:version_h
       'target_name': 'widevine_cdm_version_h',
       'type': 'none',
       'copies': [{
         'destination': '<(SHARED_INTERMEDIATE_DIR)',
         'files': [ '<(widevine_cdm_version_h_file)' ],
       }],
     },
     {
+      # GN version: //third_party/widevine/cdm:binaries
       'target_name': 'widevine_cdm_binaries',
       'type': 'none',
       'conditions': [
         [ 'OS=="mac"', {
           'xcode_settings': {
             'COPY_PHASE_STRIP': 'NO',
           }
         }],
       ],
       'copies': [{
         # TODO(ddorwin): Do we need a sub-directory? We either need a
         # sub-directory or to rename manifest.json before we can copy it.
         'destination': '<(PRODUCT_DIR)',
         'files': [ '<@(widevine_cdm_binary_files)' ],
       }],
     },
     {
       'target_name': 'widevine_test_license_server',
       'type': 'none',
       'conditions': [
         [ 'branding == "Chrome" and OS == "linux"', {
           'dependencies': [
             '<(DEPTH)/third_party/widevine/test/license_server/license_server.gyp:test_license_server',
           ],
         }],
       ],
     },
   ],
 }