[Reland #1] Don't create layout objects for children of display-none iframes.

third_party/WebKit/Source/core/layout/LayoutView.cpp

Index: third_party/WebKit/Source/core/layout/LayoutView.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutView.cpp b/third_party/WebKit/Source/core/layout/LayoutView.cpp
index b84d3ecc58a913302b327dec36d660c346fc8185..374293e898c154a038231f87d6e7e1010b63b406 100644
--- a/third_party/WebKit/Source/core/layout/LayoutView.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutView.cpp
@@ -43,6 +43,7 @@
 #include "core/paint/ViewPainter.h"
 #include "core/svg/SVGDocumentExtensions.h"
 #include "platform/Histogram.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/geometry/TransformState.h"
 #include "platform/graphics/paint/PaintController.h"
@@ -188,6 +189,15 @@ bool LayoutView::isChildAllowed(LayoutObject* child,
   return child->isBox();
 }
 
+bool LayoutView::canHaveChildren() const {
+  FrameOwner* owner = frame()->owner();
+  if (!owner)
+    return true;
+  if (!RuntimeEnabledFeatures::displayNoneIFrameCreatesNoLayoutObjectEnabled())
+    return true;
+  return !owner->isDisplayNone();
+}
+
 void LayoutView::layoutContent() {
   ASSERT(needsLayout());