[REG: Qt 5.4 -> 5.5] Dynamically deleted WebView object makes the application crash

(lldb) bt
* thread #1: tid = 0x1ce178, 0x000000010074ca9c TestWebView`QQuickItem::~QQuickItem(this=0x000000017467ee80) + 452 at qquickitem.cpp:2248, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0xbadd875d60b7bf15)
    frame #0: 0x000000010074ca9c TestWebView`QQuickItem::~QQuickItem(this=0x000000017467ee80) + 452 at qquickitem.cpp:2248
    frame #1: 0x000000010048f744 TestWebView`QQuickViewController::~QQuickViewController(this=0x000000017467ee80) + 84 at qquickviewcontroller.cpp:164
    frame #2: 0x000000010048bb90 TestWebView`QQuickWebView::~QQuickWebView(this=0x000000017467ee80) + 60 at qquickwebview.cpp:104
    frame #3: 0x0000000100486d44 TestWebView`QQmlPrivate::QQmlElement<QQuickWebView>::~QQmlElement(this=0x000000017467ee80) + 88 at qqmlprivate.h:98
  * frame #4: 0x0000000100486bc4 TestWebView`QQmlPrivate::QQmlElement<QQuickWebView>::~QQmlElement(this=0x000000017467ee80) + 28 at qqmlprivate.h:96
    frame #5: 0x0000000100486bf8 TestWebView`QQmlPrivate::QQmlElement<QQuickWebView>::~QQmlElement(this=0x000000017467ee80) + 28 at qqmlprivate.h:96
    frame #6: 0x000000010147816c TestWebView`QObjectPrivate::deleteChildren(this=0x0000000146d1e4f0) + 264 at qobject.cpp:1951
    frame #7: 0x0000000101477f04 TestWebView`QObject::~QObject(this=0x00000001740339c0) + 2216 at qobject.cpp:1031
    frame #8: 0x000000010074ce74 TestWebView`QQuickItem::~QQuickItem(this=0x00000001740339c0) + 1436 at qquickitem.cpp:2289
    frame #9: 0x00000001007c5ce0 TestWebView`QQuickRectangle::~QQuickRectangle(this=0x00000001740339c0) + 36 at qquickrectangle_p.h:128
    frame #10: 0x00000001007c5ca4 TestWebView`QQmlPrivate::QQmlElement<QQuickRectangle>::~QQmlElement(this=0x00000001740339c0) + 76 at qqmlprivate.h:98
    frame #11: 0x00000001007c5b9c TestWebView`QQmlPrivate::QQmlElement<QQuickRectangle>::~QQmlElement(this=0x00000001740339c0) + 28 at qqmlprivate.h:96
    frame #12: 0x00000001007c5bd0 TestWebView`QQmlPrivate::QQmlElement<QQuickRectangle>::~QQmlElement(this=0x00000001740339c0) + 28 at qqmlprivate.h:96
    frame #13: 0x0000000101478dec TestWebView`qDeleteInEventHandler(o=0x00000001740339c0) + 56 at qobject.cpp:4460
    frame #14: 0x00000001014789d4 TestWebView`QObject::event(this=0x00000001740339c0, e=0x0000000170625560) + 300 at qobject.cpp:1237
    frame #15: 0x000000010075af64 TestWebView`QQuickItem::event(this=0x00000001740339c0, ev=0x0000000170625560) + 1212 at qquickitem.cpp:7294
    frame #16: 0x000000010006a590 TestWebView`QApplicationPrivate::notify_helper(this=0x0000000146e20a30, receiver=0x00000001740339c0, e=0x0000000170625560) + 396 at qapplication.cpp:3717
    frame #17: 0x000000010006c4e4 TestWebView`QApplication::notify(this=0x000000016fdf3ed0, receiver=0x00000001740339c0, e=0x0000000170625560) + 1656 at qapplication.cpp:3161
    frame #18: 0x00000001014399f0 TestWebView`QCoreApplication::notifyInternal(this=0x000000016fdf3ed0, receiver=0x00000001740339c0, event=0x0000000170625560) + 192 at qcoreapplication.cpp:965
    frame #19: 0x000000010007266c TestWebView`QCoreApplication::sendEvent(receiver=0x00000001740339c0, event=0x0000000170625560) + 112 at qcoreapplication.h:224
    frame #20: 0x000000010143ae4c TestWebView`QCoreApplicationPrivate::sendPostedEvents(receiver=0x0000000000000000, event_type=0, data=0x00000001740d5ee0) + 1336 at qcoreapplication.cpp:1593
    frame #21: 0x000000010143a2e0 TestWebView`QCoreApplication::sendPostedEvents(receiver=0x0000000000000000, event_type=0) + 52 at qcoreapplication.cpp:1451
    frame #22: 0x0000000100043570 TestWebView`QEventDispatcherCoreFoundation::processPostedEvents(this=0x00000001741a32c0) + 236 at qeventdispatcher_cf.mm:384
    frame #23: 0x0000000100046068 TestWebView`RunLoopSource<QEventDispatcherCoreFoundation>::process(info=0x00000001741a32d0) + 108 at qeventdispatcher_cf_p.h:139
    frame #24: 0x0000000185b70240 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24
    frame #25: 0x0000000185b6f4e4 CoreFoundation`__CFRunLoopDoSources0 + 264
    frame #26: 0x0000000185b6d594 CoreFoundation`__CFRunLoopRun + 712
    frame #27: 0x0000000185a992d4 CoreFoundation`CFRunLoopRunSpecific + 396
    frame #28: 0x000000018f4ef6fc GraphicsServices`GSEventRunModal + 168
    frame #29: 0x000000018a696f40 UIKit`UIApplicationMain + 1488
    frame #30: 0x0000000100016d40 TestWebView`main(argc=1, argv=0x000000016fdf79e0) + 516 at qioseventdispatcher.mm:224
    frame #31: 0x0000000197f2ea08 libdyld.dylib`start + 4