IDL compiler: sync Python to r162830

Sync to:
Remove usage of deprecated V8 APIs from bindings code generator
https://codereview.chromium.org/94833002

BUG=239771
NOTRY=true
TBR=haraken

Review URL: https://codereview.chromium.org/98073002

git-svn-id: svn://svn.chromium.org/blink/trunk@162938 bbb929c8-8fbe-4397-9dbb-9b2b20218538