Don't create layout objects for children of display-none iframes.

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 733298fd28a216b3496cf0b0ba58fabbf04d3dc4..cd929dc69c5fd5979c526928a7be13e77c63a3da 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -4458,13 +4458,21 @@ HTMLFrameOwnerElement* Document::localOwner() const {
 
 void Document::willChangeFrameOwnerProperties(int marginWidth,
                                               int marginHeight,
-                                              ScrollbarMode scrollingMode) {
-  if (!body())
+                                              ScrollbarMode scrollingMode,
+                                              bool isDisplayNone) {
+  if (!documentElement())
     return;
 
   DCHECK(frame() && frame()->owner());
   FrameOwner* owner = frame()->owner();
 
+  if (isDisplayNone != owner->isDisplayNone()) {
+    documentElement()->lazyReattachIfAttached();
+  }
+
+  if (!body())
+    return;
+
   if (marginWidth != owner->marginWidth())
     body()->setIntegralAttribute(marginwidthAttr, marginWidth);
   if (marginHeight != owner->marginHeight())