Issue 6371 - Update buildtools dep. to c830dfa08e2f, use AMO-signing API

ensure_dependencies.py

 #!/usr/bin/env python
 
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 import sys
 import os
 import posixpath
 import re
@@ skipping 29 matching lines @@
   adblockpluschrome = git:git@github.com:user/adblockpluschrome.git@1fad3a7
 '''
 
 SKIP_DEPENDENCY_UPDATES = os.environ.get(
     'SKIP_DEPENDENCY_UPDATES', ''
 ).lower() not in ('', '0', 'false')
 
 NPM_LOCKFILE = '.npm_install_lock'
 
 
-class Mercurial():
+class Mercurial:
     def istype(self, repodir):
         return os.path.exists(os.path.join(repodir, '.hg'))
 
     def clone(self, source, target):
         if not source.endswith('/'):
             source += '/'
         subprocess.check_call(['hg', 'clone', '--quiet', '--noupdate', source, target])
 
     def get_revision_id(self, repo, rev=None):
         command = ['hg', 'id', '--repository', repo, '--id']
@@ skipping 26 matching lines @@
         with open(config_path, 'w') as stream:
             config.write(stream)
 
         module = os.path.relpath(target, repo)
         _ensure_line_exists(ignore_path, module)
 
     def postprocess_url(self, url):
         return url
 
 
-class Git():
+class Git:
     def istype(self, repodir):
         return os.path.exists(os.path.join(repodir, '.git'))
 
     def clone(self, source, target):
         source = source.rstrip('/')
         if not source.endswith('.git'):
             source += '.git'
         subprocess.check_call(['git', 'clone', '--quiet', source, target])
 
     def get_revision_id(self, repo, rev='HEAD'):
@@ skipping 163 matching lines @@
             return
     except IOError:
         return
 
     try:
         # Create an empty file, which gets deleted after successfully
         # installing Node.js dependencies.
         lockfile_path = os.path.join(target, NPM_LOCKFILE)
         open(lockfile_path, 'a').close()
 
-        cmd = ['npm', 'install', '--only=production', '--loglevel=warn',
+        if os.name == 'nt':
+            # Windows' CreateProcess() (called by subprocess.Popen()) only
+            # resolves executables ending in .exe. The windows installation of
+            # Node.js only provides a npm.cmd, which is executable but won't
+            # be recognized as such by CreateProcess().
+            npm_exec = 'npm.cmd'
+        else:
+            npm_exec = 'npm'
+
+        cmd = [npm_exec, 'install', '--only=production', '--loglevel=warn',
                '--no-package-lock', '--no-optional']
         subprocess.check_output(cmd, cwd=target)
 
         repo_types[vcs].ignore(os.path.join(target, NPM_LOCKFILE), target)
         repo_types[vcs].ignore(os.path.join(target, 'node_modules'), target)
 
         os.remove(lockfile_path)
     except OSError as e:
         import errno
         if e.errno == errno.ENOENT:
@@ skipping 137 matching lines @@
     args = parser.parse_args()
 
     if args.quiet:
         logging.disable(logging.INFO)
 
     repos = args.repos
     if not len(repos):
         repos = [os.path.dirname(__file__)]
     for repo in repos:
         resolve_deps(repo)