[Qt] Layer violation: qt_runtime.cpp accesses QWebElement and QTDRTNode https://bugs.webkit.org/show_bug.cgi?id=72595

Reviewed by Noam Rosenthal.

Source/WebCore:

Removed QWebElement and QtDRTNode usage that reached from WebCore into
WebKit/qt and replaced it with the ability to register custom JSValue
conversion functions. The old code has been moved to WebKit/qt.

* bridge/qt/qt_instance.cpp:
(JSC::Bindings::QtInstance::QtInstance): Remove unnecessary meta type registration
(now done in QtWebElementRuntime::initialize in WebKit/qt).
* bridge/qt/qt_runtime.cpp:
(JSC::Bindings::registerCustomType):
(JSC::Bindings::convertValueToQVariant):
(JSC::Bindings::convertQVariantToValue):
* bridge/qt/qt_runtime.h:

Source/WebKit:

* WebKit.pri: Add qwebelement_p.h to HEADERS.

Source/WebKit/qt:

Move QWebElement and QtDRTNode JS bindings from WebCore to WebKit/qt.

* Api/qwebelement.cpp: Add QWebElement to JSValue and JSValue to QWebElement
conversion through intermediate QVariant.
(QtWebElementRuntime::create):
(QtWebElementRuntime::get):
(convertJSValueToWebElementVariant):
(convertWebElementVariantToJSValue):
(QtWebElementRuntime::initialize): Register conversion functions for QWebElement.
* Api/qwebelement.h:
* Api/qwebelement_p.h: Added.
* Api/qwebpage.cpp:
(QWebPagePrivate::QWebPagePrivate): Initialize QWebElement conversion functions for
the JS runtime.
* WebCoreSupport/DumpRenderTreeSupportQt.cpp: Add QtDRTNode to JSValue and JSValue to
QtDRTNode conversion through intermediate QVariant.
(QtDRTNodeRuntime::create):
(QtDRTNodeRuntime::get):
(convertJSValueToNodeVariant):
(convertNodeVariantToJSValue):
(QtDRTNodeRuntime::initialize):
(DumpRenderTreeSupportQt::initialize): Register conversion functions for QtDRTNode.
* WebCoreSupport/DumpRenderTreeSupportQt.h:

Tools:

* DumpRenderTree/qt/DumpRenderTreeQt.cpp:
(WebCore::DumpRenderTree::DumpRenderTree): Use new initialize() function to
ensure the registration of the DRTNode JS bindings.
* DumpRenderTree/qt/LayoutTestControllerQt.cpp:
(LayoutTestController::LayoutTestController): Remove unnecessary explicit qt meta type
registration of QWebElement (now done implicitly through QWebPage ->
QtWebElementRunTime::initialize code path)

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@100658 268f45cc-cd09-0410-ab3c-d52691b4dbfc