--- a/taskcluster/docs/attributes.rst
+++ b/taskcluster/docs/attributes.rst
@@ -124,21 +124,16 @@ Signals whether the task is part of a ni
 out nightly tasks from full task set at target stage.
 
 all_locales
 ===========
 
 For the ``l10n`` and ``nightly-l10n`` kinds, this attribute contains the list
 of relevant locales for the platform.
 
-all_locales_with_changesets
-===========================
-
-Contains a dict of l10n changesets, mapped by locales (same as in ``all_locales``).
-
 l10n_chunk
 ==========
 For the ``l10n`` and ``nightly-l10n`` kinds, this attribute contains the chunk
 number of the job. Note that this is a string!
 
 chunk_locales
 =============
 For the ``l10n`` and ``nightly-l10n`` kinds, this attribute contains an array of

--- a/taskcluster/taskgraph/transforms/l10n.py
+++ b/taskcluster/taskgraph/transforms/l10n.py
@@ -3,17 +3,16 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 """
 Do transforms specific to l10n kind
 """
 
 from __future__ import absolute_import, print_function, unicode_literals
 
 import copy
-import json
 
 from mozbuild.chunkify import chunkify
 from taskgraph.transforms.base import (
     TransformSequence,
 )
 from taskgraph.util.schema import (
     validate_schema,
     optionally_keyed_by,
@@ -132,34 +131,24 @@ l10n_description_schema = Schema({
 transforms = TransformSequence()
 
 
 def _parse_locales_file(locales_file, platform=None):
     """ Parse the passed locales file for a list of locales.
         If platform is unset matches all platforms.
     """
     locales = []
-
-    with open(locales_file, mode='r') as f:
-        if locales_file.endswith('json'):
-            all_locales = json.load(f)
-            # XXX Only single locales are fetched
-            locales = {locale: data['revision'] for locale, data in all_locales.items() if 'android' in data['platforms']}
-        else:
-            all_locales = f.read().split()
-            # 'default' is the hg revision at the top of hg repo, in this context
-            locales = {locale: 'default' for locale in all_locales}
+    if locales_file.endswith('json'):
+        # Release process uses .json for locale files sometimes.
+        raise NotImplementedError("Don't know how to parse a .json locales file")
+    else:
+        with open(locales_file, mode='r') as lf:
+            locales = lf.read().split()
     return locales
 
-def _remove_ja_jp_mac_locale(locales):
-    # ja-JP-mac is a mac-only locale, but there are no mac builds being repacked, so just omit it unconditionally
-    return {
-        locale: revision for locale, revision in locales.items() if locale != 'ja-JP-mac'
-    }
-
 
 @transforms.add
 def setup_name(config, jobs):
     for job in jobs:
         dep = job['dependent-task']
         if dep.attributes.get('nightly'):
             # Set the name to the same as the dep task, without kind name.
             # Label will get set automatically with this kinds name.
@@ -238,62 +227,62 @@ def handle_keyed_by(config, jobs):
         for field in fields:
             resolve_keyed_by(item=job, field=field, item_name=job['name'])
         yield job
 
 
 @transforms.add
 def all_locales_attribute(config, jobs):
     for job in jobs:
-        locales_with_changesets = _parse_locales_file(job["locales-file"])
-        locales_with_changesets = _remove_ja_jp_mac_locale(locales_with_changesets)
-
-        locales = sorted(locales_with_changesets.keys())
+        locales = set(_parse_locales_file(job["locales-file"]))
+        # ja-JP-mac is a mac-only locale, but there are no
+        # mac builds being repacked, so just omit it unconditionally
+        locales = locales - set(("ja-JP-mac", ))
+        # Convert to mutable list.
+        locales = list(sorted(locales))
         attributes = job.setdefault('attributes', {})
         attributes["all_locales"] = locales
-        attributes["all_locales_with_changesets"] = locales_with_changesets
         yield job
 
 
 @transforms.add
 def chunk_locales(config, jobs):
     """ Utilizes chunking for l10n stuff """
     for job in jobs:
         chunks = job.get('chunks')
-        locales_with_changesets = job['attributes']['all_locales_with_changesets']
+        all_locales = job['attributes']['all_locales']
         if chunks:
-            if chunks > len(locales_with_changesets):
+            if chunks > len(all_locales):
                 # Reduce chunks down to the number of locales
-                chunks = len(locales_with_changesets)
+                chunks = len(all_locales)
             for this_chunk in range(1, chunks + 1):
                 chunked = copy.deepcopy(job)
                 chunked['name'] = chunked['name'].replace(
                     '/', '-{}/'.format(this_chunk), 1
                 )
                 chunked['mozharness']['options'] = chunked['mozharness'].get('options', [])
-                # chunkify doesn't work with dicts
-                locales_with_changesets_as_list = locales_with_changesets.items()
-                chunked_locales = chunkify(locales_with_changesets_as_list, this_chunk, chunks)
+                my_locales = []
+                my_locales = chunkify(all_locales, this_chunk, chunks)
                 chunked['mozharness']['options'].extend([
-                    'locale={}:{}'.format(locale, changeset) for locale, changeset in chunked_locales
-                ])
+                    "locale={}".format(locale) for locale in my_locales
+                    ])
                 chunked['attributes']['l10n_chunk'] = str(this_chunk)
-                chunked['attributes']['chunk_locales'] = [locale for locale, _ in chunked_locales]  # strip revision
+                chunked['attributes']['chunk_locales'] = my_locales
 
                 # add the chunk number to the TH symbol
                 group, symbol = split_symbol(
                     chunked.get('treeherder', {}).get('symbol', ''))
                 symbol += str(this_chunk)
                 chunked['treeherder']['symbol'] = join_symbol(group, symbol)
                 yield chunked
         else:
             job['mozharness']['options'] = job['mozharness'].get('options', [])
             job['mozharness']['options'].extend([
-                'locale={}:{}'.format(locale, changeset) for locale, changeset in locales_with_changesets.items()
-            ])
+                "locale={}".format(locale) for locale in all_locales
+                ])
             yield job
 
 
 @transforms.add
 def mh_config_replace_project(config, jobs):
     """ Replaces {project} in mh config entries with the current project """
     # XXXCallek This is a bad pattern but exists to satisfy ease-of-porting for buildbot
     for job in jobs: