Issue 6552 - Support arbitrary manifest values

packagerChrome.py

 # 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 errno
 import glob
 import io
 import json
 import os
 import re
@@ skipping 116 matching lines @@
     if params['type'] == 'gecko':
         templateData['app_id'] = get_app_id(params['releaseBuild'], metadata)
 
     manifest = template.render(templateData)
 
     # Normalize JSON structure
     licenseComment = re.compile(r'/\*.*?\*/', re.S)
     data = json.loads(re.sub(licenseComment, '', manifest, 1))
     if '_dummy' in data:
         del data['_dummy']
-    manifest = json.dumps(metadata.section_as_dict('manifest', data),
-                          sort_keys=True, indent=2)
+
+    metadata.serialize_section_if_present('manifest', data)
+    manifest = json.dumps(data, sort_keys=True, indent=2)
 
     return manifest.encode('utf-8')
 
 
 def toJson(data):
     return json.dumps(
         data, ensure_ascii=False, sort_keys=True,
         indent=2, separators=(',', ': ')
     ).encode('utf-8') + '\n'
 
@@ skipping 237 matching lines @@
     if devenv:
         add_devenv_requirements(files, metadata, params)
 
     zipdata = files.zipToString()
     signature = None
     pubkey = None
     if keyFile != None:
         signature = signBinary(zipdata, keyFile)
         pubkey = getPublicKey(keyFile)
     writePackage(outFile, pubkey, signature, zipdata)