Binding: Use ScriptState::forMainWorld in V8NPObject::mainWorldScriptState
Binding: Use ScriptState::forMainWorld in V8NPObject::mainWorldScriptState

BUG=506440

Review URL: https://codereview.chromium.org/1216413003

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@198193 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk