First pass at deleting paint invalidation code.

sky/engine/core/frame/FrameView.cpp

Index: sky/engine/core/frame/FrameView.cpp
diff --git a/sky/engine/core/frame/FrameView.cpp b/sky/engine/core/frame/FrameView.cpp
index 8eaf22f4cedf81f665abbbde280e70330280f08b..5ff554bfe60b666ba53dc2b55056a62d6cad1fae 100644
--- a/sky/engine/core/frame/FrameView.cpp
+++ b/sky/engine/core/frame/FrameView.cpp
@@ -371,11 +371,6 @@ void FrameView::layout(bool allowSubtree)
         performLayout(rootForThisLayout, inSubtreeLayout);
 
         m_layoutSubtreeRoot = 0;
-        // We need to ensure that we mark up all renderers up to the RenderView
-        // for paint invalidation. This simplifies our code as we just always
-        // do a full tree walk.
-        if (RenderObject* container = rootForThisLayout->container())
-            container->setMayNeedPaintInvalidation(true);
     } // Reset m_layoutSchedulingEnabled to its previous value.
 
     layer->updateLayerPositionsAfterLayout();