IDL Compiler: Make empty dict value dict()

We used object() as a python value for empty dictionary literal "{}".
But it doesn't work with (current) make_copy() well.

This CL changes the value as dict() to work with make_copy() and
describe its actual type better.


Bug: 984949, 839389
Change-Id: I3f14319bae91ab3b7510636cca103ca25f6b6424
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1826067Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Commit-Queue: Hitoshi Yoshida <peria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700121}

third_party/blink/renderer/bindings/scripts/web_idl/ir_builder.py

@@ -484,7 +484,7 @@ class _IRBuilder(object):
             idl_type = factory.simple_type(
                 name='object', debug_info=debug_info)
             assert value_token == '{}'
-            value = object()
+            value = dict()
             literal = '{}'
         else:
             assert False, 'Unknown literal type: {}'.format(type_token)

third_party/blink/renderer/bindings/scripts/web_idl/literal_constant.py

@@ -47,7 +47,7 @@ class LiteralConstant(object):
         The values of the following literals are represented as follows.
         - null: None
         - []: list()
-        - {}: object()
+        - {}: dict()
         - true / false: True / False
         - INTEGER_NUMERICS: an instance of long
         - FLOATING_POINTS: an instance of float