Remove 'read_only': 1 from most .isolate files.

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 355 matching lines @@
       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%s.isolated' % (path, os.sep, target)),
             '--isolate',
             self.ToSrcRelPath('%s%s%s.isolate' % (path, os.sep, target)),
@@ skipping 351 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)