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

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

 // 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.
 
 #include "core/dom/StyleChangeReason.h"
 
 #include "platform/tracing/TraceEvent.h"
 #include "wtf/StaticConstructors.h"
 
 namespace blink {
 
 namespace StyleChangeReason {
 const char ActiveStylesheetsUpdate[] = "ActiveStylesheetsUpdate";
 const char Animation[] = "Animation";
 const char Attribute[] = "Attribute";
 const char CleanupPlaceholderStyles[] = "CleanupPlaceholderStyles";
 const char CompositorProxy[] = "CompositorProxy";
 const char ControlValue[] = "ControlValue";
 const char Control[] = "Control";
 const char DeclarativeContent[] = "Extension declarativeContent.css";
 const char DesignMode[] = "DesignMode";
 const char FontSizeChange[] = "FontSizeChange";
 const char Fonts[] = "Fonts";
 const char FullScreen[] = "FullScreen";
+const char IFrameDisplayChanged[] = "IFrameDisplayChanged";
 const char Inline[] = "Inline";
 const char InlineCSSStyleMutated[] = "Inline CSS style declaration was mutated";
 const char Inspector[] = "Inspector";
 const char Language[] = "Language";
 const char LinkColorChange[] = "LinkColorChange";
 const char PlatformColorChange[] = "PlatformColorChange";
 const char PropagateInheritChangeToDistributedNodes[] =
     "PropagateInheritChangeToDistributedNodes";
 const char PropertyRegistration[] = "PropertyRegistration";
 const char PropertyUnregistration[] = "PropertyUnregistration";
@@ skipping 28 matching lines @@
   new (NotNull, (void*)&Drag) AtomicString(":-webkit-drag");
   new (NotNull, (void*)&Focus) AtomicString(":focus");
   new (NotNull, (void*)&Hover) AtomicString(":hover");
   new (NotNull, (void*)&Past) AtomicString(":past");
   new (NotNull, (void*)&Unresolved) AtomicString(":unresolved");
 }
 
 }  // namespace StyleChangeExtraData
 
 }  // namespace blink