Reland: Add support for entering/exiting HTML fullscreen from OOPIFs.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 3038 matching lines @@
     setAttribute(attributeName, AtomicString::number(value));
 }
 
 void Element::setContainsFullScreenElement(bool flag)
 {
     setElementFlag(ContainsFullScreenElement, flag);
     document().styleEngine().ensureFullscreenUAStyle();
     pseudoStateChanged(CSSSelector::PseudoFullScreenAncestor);
 }
 
-static Element* parentCrossingFrameBoundaries(Element* element)
+// Unlike Node::parentNode, this can cross frame boundaries.
+static Element* nextAncestorElement(Element* element)
 {
     DCHECK(element);
-    return element->parentElement() ? element->parentElement() : element->document().localOwner();
+    if (element->parentElement())
+        return element->parentElement();
+
+    Frame* frame = element->document().frame();
+    if (!frame || !frame->owner())
+        return nullptr;
+
+    // Find the next LocalFrame on the ancestor chain, and return the
+    // corresponding <iframe> element for the remote child if it exists.
+    while (frame->tree().parent() && frame->tree().parent()->isRemoteFrame())
+        frame = frame->tree().parent();
+
+    if (frame->owner() && frame->owner()->isLocal())
+        return toHTMLFrameOwnerElement(frame->owner());
+
+    return nullptr;
 }
 
 void Element::setContainsFullScreenElementOnAncestorsCrossingFrameBoundaries(bool flag)
 {
-    for (Element* element = parentCrossingFrameBoundaries(this); element; element = parentCrossingFrameBoundaries(element))
+    for (Element* element = nextAncestorElement(this); element; element = nextAncestorElement(element))
         element->setContainsFullScreenElement(flag);
 }
 
 void Element::setIsInTopLayer(bool inTopLayer)
 {
     if (isInTopLayer() == inTopLayer)
         return;
     setElementFlag(IsInTopLayer, inTopLayer);
 
     // We must ensure a reattach occurs so the layoutObject is inserted in the correct sibling order under LayoutView according to its
@@ skipping 629 matching lines @@
 
 DEFINE_TRACE_WRAPPERS(Element)
 {
     if (hasRareData()) {
         visitor->traceWrappers(elementRareData());
     }
     ContainerNode::traceWrappers(visitor);
 }
 
 } // namespace blink