IDL compiler: sync Python to r162980

Python side to:
Reverse order of arguments to v8String.
https://codereview.chromium.org/96533006/

BUG=239771
BUG=324225
NOTRY=true
TBR=haraken

Review URL: https://codereview.chromium.org/100853002

git-svn-id: svn://svn.chromium.org/blink/trunk@163046 bbb929c8-8fbe-4397-9dbb-9b2b20218538