Fix compile on Windows swarming bot

infra/bots/flavor/default_flavor.py

 #!/usr/bin/env python
 #
 # Copyright 2016 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 
 """Default flavor utils class, used for desktop bots."""
 
@@ skipping 51 matching lines @@
   work. Each build step flavor should correspond to a subclass of
   DefaultFlavorUtils which may override any of these functions as appropriate
   for that flavor.
 
   For example, the AndroidFlavorUtils will override the functions for
   copying files between the host and Android device, as well as the
   'step' function, so that commands may be run through ADB.
   """
   def __init__(self, bot_info, *args, **kwargs):
     self._bot_info = bot_info
-    self.chrome_path = os.path.join(os.path.expanduser('~'), 'src')
+    self.chrome_path = os.path.join(self._bot_info.build_dir, 'src')
 
   def run(self, cmd, **kwargs):
     """Runs a step as appropriate for this flavor."""
     path_to_app = os.path.join(self._bot_info.out_dir,
                                self._bot_info.configuration, cmd[0])
     if (sys.platform == 'linux' and
         'x86_64' in self._bot_info.bot_name and
         not 'TSAN' in self._bot_info.bot_name):
       new_cmd = ['catchsegv', path_to_app]
     else:
       new_cmd = [path_to_app]
     new_cmd.extend(cmd[1:])
     return self._bot_info.run(new_cmd, **kwargs)
 
+  def bootstrap_win_toolchain(self):
+    """Run bootstrapping script for the Windows toolchain."""
+    bootstrap_script = os.path.join(self._bot_info.infrabots_dir,
+                                    'bootstrap_win_toolchain_json.py')
+    win_toolchain_json = os.path.join(
+        self._bot_info.build_dir, 'src', 'build', 'win_toolchain.json')
+    self._bot_info.run([
+        'python', bootstrap_script,
+        '--win_toolchain_json', win_toolchain_json,
+        '--depot_tools_parent_dir', self._bot_info.build_dir])
 
   def compile(self, target):
     """Build the given target."""
     # The CHROME_PATH environment variable is needed for bots that use
     # toolchains downloaded by Chrome.
-    env = {'CHROME_PATH': self.chrome_path}
+    env = {}
     if sys.platform == 'win32':
       make_cmd = ['python', 'make.py']
+      env['CHROME_PATH'] = self.chrome_path
+      self._bot_info._run_once(self.bootstrap_win_toolchain)
     else:
       make_cmd = ['make']
     cmd = make_cmd + [target]
     self._bot_info.run(cmd, env=env)
 
   def device_path_join(self, *args):
     """Like os.path.join(), but for paths on a connected device."""
     return os.path.join(*args)
 
   def device_path_exists(self, path):
@@ skipping 59 matching lines @@
     return DeviceDirs(
         dm_dir=os.path.join(self._bot_info.swarm_out_dir, 'dm'),
         perf_data_dir=self._bot_info.perf_data_dir,
         resource_dir=self._bot_info.resource_dir,
         images_dir=join('images'),
         skp_dir=self._bot_info.local_skp_dir,
         tmp_dir=join('tmp'))
 
   def __repr__(self):
     return '<%s object>' % self.__class__.__name__  # pragma: no cover