Fix various windows-isms in the MB gen code paths.

tools/mb/mb.py

 #!/usr/bin/env python
 # Copyright 2015 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.
 
 """MB - the Meta-Build wrapper around GYP and GN
 
 MB is a wrapper script for GYP and GN that can be used to generate build files
 for sets of canned configurations and analyze them.
 """
@@ skipping 332 matching lines @@
 
       # Since GN hasn't run yet, the build directory may not even exist.
       self.MaybeMakeDirectory(self.ToAbsPath(path))
 
       self.WriteFile(gn_runtime_deps_path, '\n'.join(gn_labels) + '\n')
       cmd.append('--runtime-deps-list-file=%s' % gn_runtime_deps_path)
 
     ret, _, _ = self.Run(cmd)
 
     for target in swarming_targets:
-      deps_path = self.ToAbsPath(path, target + '.runtime_deps')
+      if sys.platform == 'win32':
+        deps_path = self.ToAbsPath(path, target + '.exe.runtime_deps')
+      else:
+        deps_path = self.ToAbsPath(path, target + '.runtime_deps')
       if not self.Exists(deps_path):
           raise MBErr('did not generate %s' % deps_path)
 
       command, extra_files = self.GetIsolateCommand(target, vals)
 
       runtime_deps = self.ReadFile(deps_path).splitlines()
 
       isolate_path = self.ToAbsPath(path, target + '.isolate')
       self.WriteFile(isolate_path,
         pprint.pformat({
           'variables': {
             'command': command,
             'files': sorted(runtime_deps + extra_files),
             'read_only': 1,
           }
         }) + '\n')
 
       self.WriteJSON(
         {
           'args': [
             '--isolated',
-            self.ToSrcRelPath('%s/%s.isolated' % (path, target)),
+            self.ToSrcRelPath('%s%s%s.isolated' % (path, os.sep, target)),
             '--isolate',
-            self.ToSrcRelPath('%s/%s.isolate' % (path, target)),
+            self.ToSrcRelPath('%s%s%s.isolate' % (path, os.sep, target)),
           ],
           'dir': self.chromium_src_dir,
           'version': 1,
         },
         isolate_path + 'd.gen.json',
       )
 
 
     return ret
 
@@ skipping 162 matching lines @@
 
   def ToAbsPath(self, build_path, *comps):
     return os.path.join(self.chromium_src_dir,
                         self.ToSrcRelPath(build_path),
                         *comps)
 
   def ToSrcRelPath(self, path):
     """Returns a relative path from the top of the repo."""
     # TODO: Support normal paths in addition to source-absolute paths.
     assert(path.startswith('//'))
-    return path[2:]
+    return path[2:].replace('/', os.sep)
 
   def ParseGYPConfigPath(self, path):
     rpath = self.ToSrcRelPath(path)
     output_dir, _, config = rpath.rpartition('/')
     self.CheckGYPConfigIsSupported(config, path)
     return output_dir, config
 
   def CheckGYPConfigIsSupported(self, config, path):
     if config not in ('Debug', 'Release'):
       if (sys.platform in ('win32', 'cygwin') and
@@ skipping 206 matching lines @@
 
 if __name__ == '__main__':
   try:
     sys.exit(main(sys.argv[1:]))
   except MBErr as e:
     print(e)
     sys.exit(1)
   except KeyboardInterrupt:
     print("interrupted, exiting", stream=sys.stderr)
     sys.exit(130)