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
Remove dead code in core/events/.

This CL removes the following dead code:
- ClipboardEvent::create()
- CompositionEvent::CompositionEvent(const AtomicString&, PassRefPtr<AbstractView>, const String&)
- CompositionEvent::create(const AtomicString&, PassRefPtr<AbstractView>, const String&)
- Event::clipboardData
- Event::clipboard
- EventTarget::isFiringEventListeners
- GestureEvent::create()
- GestureEvent::initGestureEvent
- findKeyboardEvent in KeybaordEvent.{cpp,h}
- MouseEvent::create(const AtomicString&, bool, bool, PassRefPtr<AbstractView>,
                     int, int, int, int, int, int, int, bool, bool, bool, bool,
		     unsigned short, PassRefPtr<EventTarget>)
- MouseEvent::clipboard
- MouseRelatedEvent::pageLocation
- NodeEventContext::currentTarget
- NodeEventContext::treeScopeEventContext
- OverflowEvent::initOverflowEvent
- TextEvent::isBackTab

BUG=none
TEST=none; no behavior changes.

Review URL: https://codereview.chromium.org/151123002

git-svn-id: svn://svn.chromium.org/blink/trunk@166274 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Revert egov.uscis.gov site quirk.

Site has changed, hence the 'required=no' workaround no longer needed.

R=
BUG=154611

Review URL: https://codereview.chromium.org/141713006

git-svn-id: svn://svn.chromium.org/blink/trunk@166275 bbb929c8-8fbe-4397-9dbb-9b2b20218538
plugins/plugin-document-back-forward.html is flaky

BUG=340150
TBR=caseq@chromium.org

Review URL: https://codereview.chromium.org/152413002

git-svn-id: svn://svn.chromium.org/blink/trunk@166276 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Pass an Isolate around in context related methods

Review URL: https://codereview.chromium.org/151283002

git-svn-id: svn://svn.chromium.org/blink/trunk@166277 bbb929c8-8fbe-4397-9dbb-9b2b20218538
virtual/implsidepainting/inspector/timeline/timeline-dom-content-loaded-event.html crashes

BUG=298188
TBR=caseq

Review URL: https://codereview.chromium.org/148443007

git-svn-id: svn://svn.chromium.org/blink/trunk@166278 bbb929c8-8fbe-4397-9dbb-9b2b20218538