Allow paint invalidation containers to cross frame boundaries. (re-land #2)

Source/core/rendering/RenderLayerRepainter.cpp

Index: Source/core/rendering/RenderLayerRepainter.cpp
diff --git a/Source/core/rendering/RenderLayerRepainter.cpp b/Source/core/rendering/RenderLayerRepainter.cpp
index d885c7b38f59a36b863bfebedf941558db8fe969..481dc1dbf47752d864a804062bc8e87a4a7d734f 100644
--- a/Source/core/rendering/RenderLayerRepainter.cpp
+++ b/Source/core/rendering/RenderLayerRepainter.cpp
@@ -110,23 +110,7 @@ void RenderLayerRepainter::setBackingNeedsPaintInvalidationInRect(const LayoutRe
     // https://bugs.webkit.org/show_bug.cgi?id=61159 describes an unreproducible crash here,
     // so assert but check that the layer is composited.
     ASSERT(m_renderer.compositingState() != NotComposited);
-    if (m_renderer.compositingState() == NotComposited) {
-        // If we're trying to issue paint invalidations of the placeholder document layer, propagate the
-        // paint invalidation to the native view system.
-        LayoutRect absRect(r);
-        LayoutPoint delta;
-        m_renderer.layer()->convertToLayerCoords(m_renderer.layer()->root(), delta);
-        absRect.moveBy(delta);
-
-        if (absRect.isEmpty())
-            return;
-
-        RenderView* view = m_renderer.view();
-        if (view)
-            view->invalidatePaintForRectangle(absRect);
-        return;
-    }
-    // FIXME: generalize accessors to backing GraphicsLayers so that this code is squasphing-agnostic.
+    // FIXME: generalize accessors to backing GraphicsLayers so that this code is squashing-agnostic.
     if (m_renderer.layer()->groupedMapping()) {
         LayoutRect paintInvalidationRect = r;
         paintInvalidationRect.move(m_renderer.layer()->subpixelAccumulation());