IDL compiler: sync Python to r166200

Python side to:
Pass an Isolate to DOMWrapperWorld::current()
https://codereview.chromium.org/151263002/

BUG=239771
TBR=haraken
NOTRY=true

Review URL: https://codereview.chromium.org/152393002

git-svn-id: svn://svn.chromium.org/blink/trunk@166273 bbb929c8-8fbe-4397-9dbb-9b2b20218538