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

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef FrameOwner_h
 #define FrameOwner_h
 
 #include "core/CoreExport.h"
 #include "core/dom/SandboxFlags.h"
 #include "platform/heap/Handle.h"
@@ skipping 30 matching lines @@
 
   // Returns the 'name' content attribute value of the browsing context
   // container.
   // https://html.spec.whatwg.org/multipage/browsers.html#browsing-context-container
   virtual AtomicString browsingContextContainerName() const = 0;
   virtual ScrollbarMode scrollingMode() const = 0;
   virtual int marginWidth() const = 0;
   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<mojom::blink::PermissionName>& delegatedPermissions()
       const = 0;
 };
 
 // TODO(dcheng): This class is an internal implementation detail of provisional
 // frames. Move this into WebLocalFrameImpl.cpp and remove existing dependencies
 // on it.
 class CORE_EXPORT DummyFrameOwner
     : public GarbageCollectedFinalized<DummyFrameOwner>,
@@ skipping 14 matching lines @@
   bool canRenderFallbackContent() const override { return false; }
   void renderFallbackContent() override {}
   AtomicString browsingContextContainerName() const override {
     return AtomicString();
   }
   ScrollbarMode scrollingMode() const override { return ScrollbarAuto; }
   int marginWidth() const override { return -1; }
   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<mojom::blink::PermissionName>& delegatedPermissions()
       const override {
     DEFINE_STATIC_LOCAL(WebVector<mojom::blink::PermissionName>, permissions,
                         ());
     return permissions;
   }
 
  private:
   // Intentionally private to prevent redundant checks when the type is
   // already DummyFrameOwner.
   bool isLocal() const override { return false; }
   bool isRemote() const override { return false; }
 };
 
 }  // namespace blink
 
 #endif  // FrameOwner_h