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 77c1366b3133990800bad1df47978b3df3500aa2..3345c0fdc8beb318535d43941143d8a39ca3e254 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -4497,13 +4497,20 @@ HTMLFrameOwnerElement* Document::localOwner() const {
 
 void Document::willChangeFrameOwnerProperties(int marginWidth,
                                               int marginHeight,
-                                              ScrollbarMode scrollingMode) {
-  if (!body())
-    return;
-
+                                              ScrollbarMode scrollingMode,
+                                              bool isDisplayNone) {
   DCHECK(frame() && frame()->owner());
   FrameOwner* owner = frame()->owner();
 
+  if (documentElement()) {
+    if (isDisplayNone != owner->isDisplayNone()) {
+      documentElement()->lazyReattachIfAttached();
+    }
+  }
+
+  if (!body())
+    return;
+
   if (marginWidth != owner->marginWidth())
     body()->setIntegralAttribute(marginwidthAttr, marginWidth);
   if (marginHeight != owner->marginHeight())