Use variable annotations everywhere (#2909)

stdlib/3/json/decoder.pyi

@@ -11,12 +11,12 @@ if sys.version_info >= (3, 5):
         def __init__(self, msg: str, doc: str, pos: int) -> None: ...
 
 class JSONDecoder:
-    object_hook = ...  # type: Callable[[Dict[str, Any]], Any]
-    parse_float = ...  # type: Callable[[str], Any]
-    parse_int = ...  # type: Callable[[str], Any]
+    object_hook: Callable[[Dict[str, Any]], Any]
+    parse_float: Callable[[str], Any]
+    parse_int: Callable[[str], Any]
     parse_constant = ...  # Callable[[str], Any]
-    strict = ...  # type: bool
-    object_pairs_hook = ...  # type: Callable[[List[Tuple[str, Any]]], Any]
+    strict: bool
+    object_pairs_hook: Callable[[List[Tuple[str, Any]]], Any]
 
     def __init__(self, object_hook: Optional[Callable[[Dict[str, Any]], Any]] = ...,
                  parse_float: Optional[Callable[[str], Any]] = ...,

stdlib/3/json/encoder.pyi

@@ -1,15 +1,15 @@
 from typing import Any, Callable, Iterator, Optional, Tuple
 
 class JSONEncoder:
-    item_separator = ...  # type: str
-    key_separator = ...  # type: str
+    item_separator: str
+    key_separator: str
 
-    skipkeys = ...  # type: bool
-    ensure_ascii = ...  # type: bool
-    check_circular = ...  # type: bool
-    allow_nan = ...  # type: bool
-    sort_keys = ...  # type: bool
-    indent = ...  # type: int
+    skipkeys: bool
+    ensure_ascii: bool
+    check_circular: bool
+    allow_nan: bool
+    sort_keys: bool
+    indent: int
 
     def __init__(self, skipkeys: bool = ..., ensure_ascii: bool = ...,
                  check_circular: bool = ..., allow_nan: bool = ..., sort_keys: bool = ...,