Sync Python IDL compiler to r162010

Add info.Holder() to ExceptionState, per
https://codereview.chromium.org/68563003

TBR=haraken
NOTRY=true

Review URL: https://codereview.chromium.org/73563002

git-svn-id: svn://svn.chromium.org/blink/trunk@162055 bbb929c8-8fbe-4397-9dbb-9b2b20218538