idl_parser: Add current directory to sys.path

Python 3 doesn't support implicit relative imports.
Fix this by adding the current directory to the search path, so all the files can be found.
This works on both Python 2 and 3.

Traceback (most recent call last):
  File "../../third_party/blink/renderer/bindings/scripts/collect_idl_files.py", line 14, in <module>
    import blink_idl_parser
  File "C:\Google\chromium\src\third_party\blink\renderer\bindings\scripts\blink_idl_parser.py", line 74, in <module>
    from idl_parser.idl_parser import IDLParser  # pylint: disable=import-error
  File "C:\Google\chromium\src\third_party\blink\renderer\bindings\scripts\..\..\..\..\..\tools\idl_parser\idl_parser.py", line 38, in <module>
    from idl_lexer import IDLLexer
ModuleNotFoundError: No module named 'idl_lexer'

Bug: 941669
Change-Id: Ib0e7c88100fd0cc1eee90d252ad8c557e1e25197
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2124475
Commit-Queue: Raul Tambre <raul@tambre.ee>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Auto-Submit: Raul Tambre <raul@tambre.ee>
Cr-Original-Commit-Position: refs/heads/master@{#755073}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: e3337bf379af36d3d886a575f7cb0e0b46bc3a66
1 file changed