Split modules-dependent Event code in core.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 0e1d09bf98b6f9254b3445e86ce16e8107ac5762..19bc21e1fb2b8a21d581f890f23677ba962b4f31 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -3912,6 +3912,9 @@ PassRefPtrWillBeRawPtr<Event> Document::createEvent(const String& eventType, Exc
     RefPtrWillBeRawPtr<Event> event = EventFactory::create(eventType);
     if (event)
         return event.release();
+    event = EventModulesFactory::create(eventType); // TODO: move this to modules http://crbug.com/358074
+    if (event)
+        return event.release();
 
     exceptionState.throwDOMException(NotSupportedError, "The provided event type ('" + eventType + "') is invalid.");
     return nullptr;