GN: support 32-bit x86 builds

infra/bots/recipe_modules/flavor/gn_flavor.py

 # Copyright 2016 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.
 
 import default_flavor
 
 """GN flavor utils, used for building Skia with GN."""
 class GNFlavorUtils(default_flavor.DefaultFlavorUtils):
   def supported(self):
     extra_config = self.m.vars.builder_cfg.get('extra_config', '')
+    os           = self.m.vars.builder_cfg.get('os',           '')
+    target_arch  = self.m.vars.builder_cfg.get('target_arch',  '')
 
     return any([
       'SAN' in extra_config,
       extra_config == 'Fast',
       extra_config == 'GN',
-      extra_config.startswith('SK')
+      extra_config.startswith('SK'),
+      os == 'Ubuntu' and target_arch == 'x86',
     ])
 
   def _run(self, title, cmd, env=None, infra_step=False):
     self.m.vars.default_env = {k: v for (k,v)
                                in self.m.vars.default_env.iteritems()
                                if k in ['PATH']}
     self.m.run(self.m.step, title, cmd=cmd,
                env=env, cwd=self.m.vars.skia_dir, infra_step=infra_step)
 
   def compile(self, unused_target, **kwargs):
     """Build Skia with GN."""
     compiler      = self.m.vars.builder_cfg.get('compiler',      '')
     configuration = self.m.vars.builder_cfg.get('configuration', '')
     extra_config  = self.m.vars.builder_cfg.get('extra_config',  '')
     os            = self.m.vars.builder_cfg.get('os',            '')
+    target_arch   = self.m.vars.builder_cfg.get('target_arch',   '')
 
     clang_linux = str(self.m.vars.slave_dir.join('clang_linux'))
 
     cc, cxx = None, None
     extra_cflags = []
     extra_ldflags = []
 
     if compiler == 'Clang' and os == 'Ubuntu':
       cc  = clang_linux + '/bin/clang'
       cxx = clang_linux + '/bin/clang++'
@@ skipping 16 matching lines @@
       args['is_debug'] = 'false'
     if extra_config == 'MSAN':
       args['skia_use_fontconfig'] = 'false'
 
     for (k,v) in {
       'cc':  cc,
       'cxx': cxx,
       'extra_cflags':  ' '.join(extra_cflags),
       'extra_ldflags': ' '.join(extra_ldflags),
       'sanitize': extra_config if 'SAN' in extra_config else '',
+      'target_cpu': 'x86' if target_arch == 'x86' else '',
     }.iteritems():
       if v:
         args[k] = '"%s"' % v
 
     gn_args = ' '.join('%s=%s' % (k,v) for (k,v) in sorted(args.iteritems()))
 
     self._run('fetch-gn', [self.m.vars.skia_dir.join('bin', 'fetch-gn')],
               infra_step=True)
     self._run('gn gen', ['gn', 'gen', self.out_dir, '--args=' + gn_args])
     self._run('ninja', ['ninja', '-C', self.out_dir])
@@ skipping 15 matching lines @@
     if 'ASAN' == extra_config:
       env[ 'ASAN_OPTIONS'] = 'symbolize=1 detect_leaks=1'
       env[ 'LSAN_OPTIONS'] = 'symbolize=1 print_suppressions=1'
       env['UBSAN_OPTIONS'] = 'symbolize=1 print_stacktrace=1'
 
     if 'MSAN' == extra_config:
       # Find the MSAN-built libc++.
       env['LD_LIBRARY_PATH'] = clang_linux + '/msan'
 
     self._run(name, cmd, env=env)