Download SwiftShader component if WebGL is blacklisted

build/common.gypi

 # Copyright (c) 2011 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 1152 matching lines @@
       ['enable_register_protocol_handler==1', {
         'defines': [
           'ENABLE_REGISTER_PROTOCOL_HANDLER=1',
         ],
       }],
       ['enable_web_intents==1', {
         'defines': [
           'ENABLE_WEB_INTENTS=1',
         ],
       }],
+      ['OS=="win" and branding=="Chrome"', {
+        'defines': ['ENABLE_SWIFTSHADER'],
+      }],
     ],  # conditions for 'target_defaults'
     'target_conditions': [
       ['enable_wexit_time_destructors==1', {
         'conditions': [
           [ 'clang==1', {
             'cflags': [
               '-Wexit-time-destructors',
             ],
             'xcode_settings': {
               'WARNING_CFLAGS': [
@@ skipping 1477 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }