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

third_party/WebKit/Source/core/frame/FrameOwner.h

Index: third_party/WebKit/Source/core/frame/FrameOwner.h
diff --git a/third_party/WebKit/Source/core/frame/FrameOwner.h b/third_party/WebKit/Source/core/frame/FrameOwner.h
index 7031b403f330b63d7710274a7ef7e2a0578415f6..ae065e4adc9f1de123298b18c10d82bc81c37350 100644
--- a/third_party/WebKit/Source/core/frame/FrameOwner.h
+++ b/third_party/WebKit/Source/core/frame/FrameOwner.h
@@ -48,6 +48,7 @@ class CORE_EXPORT FrameOwner : public GarbageCollectedMixin {
   virtual int marginHeight() const = 0;
   virtual bool allowFullscreen() const = 0;
   virtual bool allowPaymentRequest() const = 0;
+  virtual bool isDisplayNone() const = 0;
   virtual AtomicString csp() const = 0;
   virtual const WebVector<WebPermissionType>& delegatedPermissions() const = 0;
 };
@@ -81,6 +82,7 @@ class CORE_EXPORT DummyFrameOwner
   int marginHeight() const override { return -1; }
   bool allowFullscreen() const override { return false; }
   bool allowPaymentRequest() const override { return false; }
+  bool isDisplayNone() const override { return false; }
   AtomicString csp() const override { return nullAtom; }
   const WebVector<WebPermissionType>& delegatedPermissions() const override {
     DEFINE_STATIC_LOCAL(WebVector<WebPermissionType>, permissions, ());