Don't create boxes for the contents of display: none iframes.

third_party/WebKit/Source/core/html/HTMLFrameElementBase.cpp

Index: third_party/WebKit/Source/core/html/HTMLFrameElementBase.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLFrameElementBase.cpp b/third_party/WebKit/Source/core/html/HTMLFrameElementBase.cpp
index eb81d639c4de017fbb4adf4c46265078a85c0f43..b1f2ef3aa5d20cf6d092644e2169ed681161f2aa 100644
--- a/third_party/WebKit/Source/core/html/HTMLFrameElementBase.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLFrameElementBase.cpp
@@ -28,6 +28,7 @@
 #include "core/HTMLNames.h"
 #include "core/dom/Attribute.h"
 #include "core/dom/Document.h"
+#include "core/dom/StyleChangeReason.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/RemoteFrame.h"
@@ -193,11 +194,23 @@ void HTMLFrameElementBase::didNotifySubtreeInsertionsToDocument() {
 void HTMLFrameElementBase::attachLayoutTree(const AttachContext& context) {
   HTMLFrameOwnerElement::attachLayoutTree(context);
 
-  if (layoutPart()) {
-    if (Frame* frame = contentFrame()) {
-      if (frame->isLocalFrame())
-        setWidget(toLocalFrame(frame)->view());
-      else if (frame->isRemoteFrame())
+  // TODO(esprehn): Why do we only call setWidget() if the frame is
+  // displayed?
+
+  if (Frame* frame = contentFrame()) {
+    if (frame->isLocalFrame()) {
+      LocalFrame* localFrame = toLocalFrame(frame);
+      if (layoutPart())
+        setWidget(localFrame->view());
+      if (Element* documentElement =
+              localFrame->document()->documentElement()) {
+        if (static_cast<bool>(layoutPart()) !=
+            static_cast<bool>(documentElement->layoutObject())) {
+          documentElement->lazyReattachIfAttached();
+        }
+      }
+    } else {
+      if (layoutPart())
         setWidget(toRemoteFrame(frame)->view());
     }
   }