idl_parser: Stop setting DATETIME property in IdlNode instances.

This makes the build non-deterministic, as even if the IDL contents do
not change the pickled files generated by collect_idl_files.py were
changing depending on the modification time of the files.

The DATETIME property seems to have been copied from the idl_parser.py
version that originated in //ppapi/generators (which still exists and
makes use of it) even though the bindings scripts do not use it for
anything.

Fixed: 1298824
Change-Id: I902f663993540e7b7be8cc34f0a64b7ef72bf3ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3484121
Auto-Submit: Raphael Kubo Da Costa <raphael.kubo.da.costa@intel.com>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/main@{#974494}
NOKEYCHECK=True
GitOrigin-RevId: 37036c497e6d5f67d33085aa503ea1ee9a3c1292
diff --git a/idl_node.py b/idl_node.py
index d7284d8..95b745c 100755
--- a/idl_node.py
+++ b/idl_node.py
@@ -77,8 +77,8 @@
 #
 class IDLNode(object):
   VERBOSE_PROPS = [
-      'PROD', 'NAME', 'VALUE', 'TYPE',
-      'ERRORS', 'WARNINGS', 'FILENAME', 'LINENO', 'POSITION', 'DATETIME',
+      'PROD', 'NAME', 'VALUE', 'TYPE', 'ERRORS', 'WARNINGS', 'FILENAME',
+      'LINENO', 'POSITION'
   ]
 
   def __init__(self, cls, filename, lineno, pos, children=None):
diff --git a/idl_parser.py b/idl_parser.py
index 91b988f..743a31b 100755
--- a/idl_parser.py
+++ b/idl_parser.py
@@ -29,11 +29,8 @@
 # pylint: disable=R0201
 # pylint: disable=C0301
 
-from __future__ import print_function
-
 import os.path
 import sys
-import time
 
 # Can't use relative imports if we don't have a parent package.
 if __package__:
@@ -1316,7 +1313,6 @@
   with open(filename) as fileobject:
     try:
       out = parser.ParseText(filename, fileobject.read())
-      out.SetProperty('DATETIME', time.ctime(os.path.getmtime(filename)))
       out.SetProperty('ERRORS', parser.GetErrors())
       return out