<https://webkit.org/b/120210>

Reviewed by Antti Koivisto.

The RenderLayerCompositor is always created by a RenderView passing itself to the constructor.
By making m_renderView a reference, we flush out some unnecessary null checks.
We also gain a pointer-free path to Settings through m_renderView.frameView().frame().settings()
so we don't have to make those blocks conditional anymore, reducing ambiguity.

* rendering/RenderLayerCompositor.cpp:
* rendering/RenderLayerCompositor.h:
* rendering/RenderView.cpp:
(WebCore::RenderView::compositor):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@154489 268f45cc-cd09-0410-ab3c-d52691b4dbfc