Enumerate the return value of dispatchEvent so it is clear.

third_party/WebKit/Source/modules/indexeddb/IDBRequest.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 393 matching lines @@
 const AtomicString& IDBRequest::interfaceName() const
 {
     return EventTargetNames::IDBRequest;
 }
 
 ExecutionContext* IDBRequest::executionContext() const
 {
     return ActiveDOMObject::executionContext();
 }
 
-bool IDBRequest::dispatchEventInternal(PassRefPtrWillBeRawPtr<Event> event)
+WebInputEventResult IDBRequest::dispatchEventInternal(PassRefPtrWillBeRawPtr<Event> event)
 {
     IDB_TRACE("IDBRequest::dispatchEvent");
     if (m_contextStopped || !executionContext())
-        return false;
+        return WebInputEventResult::HandledSuppressed;
     ASSERT(m_readyState == PENDING);
     ASSERT(m_hasPendingActivity);
     ASSERT(m_enqueuedEvents.size());
     ASSERT(event->target() == this);
 
     ScriptState::Scope scope(m_scriptState.get());
 
     if (event->type() != EventTypeNames::blocked)
         m_readyState = DONE;
     dequeueEvent(event.get());
@@ skipping 22 matching lines @@
         m_didFireUpgradeNeededEvent = true;
     }
 
     // FIXME: When we allow custom event dispatching, this will probably need to change.
     ASSERT_WITH_MESSAGE(event->type() == EventTypeNames::success || event->type() == EventTypeNames::error || event->type() == EventTypeNames::blocked || event->type() == EventTypeNames::upgradeneeded, "event type was %s", event->type().utf8().data());
     const bool setTransactionActive = m_transaction && (event->type() == EventTypeNames::success || event->type() == EventTypeNames::upgradeneeded || (event->type() == EventTypeNames::error && !m_requestAborted));
 
     if (setTransactionActive)
         m_transaction->setActive(true);
 
-    bool dontPreventDefault = IDBEventDispatcher::dispatch(event.get(), targets);

[jsbell, 2015/12/03 00:46:18]

Very happy to see this going away. :)

[dtapuska, 2015/12/03 02:00:53]

Thanks for the happiness :-)

+    WebInputEventResult eventResult = IDBEventDispatcher::dispatch(event.get(), targets);
 
     if (m_transaction) {
         if (m_readyState == DONE)
             m_transaction->unregisterRequest(this);
 
         // Possibly abort the transaction. This must occur after unregistering (so this request
         // doesn't receive a second error) and before deactivating (which might trigger commit).
-        if (event->type() == EventTypeNames::error && dontPreventDefault && !m_requestAborted) {
+        if (event->type() == EventTypeNames::error && eventResult == WebInputEventResult::NotHandled && !m_requestAborted) {
             m_transaction->setError(m_error);
             m_transaction->abort(IGNORE_EXCEPTION);
         }
 
         // If this was the last request in the transaction's list, it may commit here.
         if (setTransactionActive)
             m_transaction->setActive(false);
     }
 
     if (cursorToNotify)
         cursorToNotify->postSuccessHandlerCallback();
 
     // An upgradeneeded event will always be followed by a success or error event, so must
     // be kept alive.
     if (m_readyState == DONE && event->type() != EventTypeNames::upgradeneeded)
         m_hasPendingActivity = false;
 
-    return dontPreventDefault;
+    return eventResult;
 }
 
 void IDBRequest::uncaughtExceptionInEventHandler()
 {
     if (m_transaction && !m_requestAborted) {
         m_transaction->setError(DOMException::create(AbortError, "Uncaught exception in event handler."));
         m_transaction->abort(IGNORE_EXCEPTION);
     }
 }
 
@@ skipping 33 matching lines @@
 
 void IDBRequest::dequeueEvent(Event* event)
 {
     for (size_t i = 0; i < m_enqueuedEvents.size(); ++i) {
         if (m_enqueuedEvents[i].get() == event)
             m_enqueuedEvents.remove(i);
     }
 }
 
 } // namespace blink