Unreviewed trivial build fix: Add missing virtual destructor to
LayerTreeRendererClient. Otherwise the build with -Werror breaks, which
complains (rightly so) that we're deleting a sub-class where the super class
doesn't have a virtual destructor.

* UIProcess/CoordinatedGraphics/LayerTreeRenderer.h:
(WebKit::LayerTreeRendererClient::~LayerTreeRendererClient):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141419 268f45cc-cd09-0410-ab3c-d52691b4dbfc
[Qt] Fix minor memory leak in slot execution

Reviewed by Allan Sandfeld Jensen.

Don't leak the "length" string when executing a slot in JavaScript.

* bridge/qt/qt_runtime.cpp:
(JSC::Bindings::QtConnectionObject::execute):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141420 268f45cc-cd09-0410-ab3c-d52691b4dbfc