Move Document.fullscreenElement to DocumentOrShadowRoot

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 194 matching lines @@
   return static_cast<Fullscreen*>(
       Supplement<Document>::from(document, supplementName()));
 }
 
 Element* Fullscreen::fullscreenElementFrom(Document& document) {
   if (Fullscreen* found = fromIfExists(document))
     return found->fullscreenElement();
   return nullptr;
 }
 
+Element* Fullscreen::fullscreenElementForBindingFrom(TreeScope& scope) {
+  Element* element = fullscreenElementFrom(scope.document());
+  if (!element || !RuntimeEnabledFeatures::fullscreenUnprefixedEnabled())
+    return element;
+
+  // TODO(kochi): Once V0 code is removed, we can use the same logic for
+  // Document and ShadowRoot.
+  if (!scope.rootNode().isShadowRoot()) {
+    // For Shadow DOM V0 compatibility: We allow returning an element in V0

[foolip, 2016/10/24 15:30:12]

Do you want to attempt all of these changes at once? If it's fine to do them
one-by-one, then just not having this code and tying the behavior change to
unprefixed Fullscreen seems OK. If not, why not the same logic for
Fullscreen::currentFullScreenElementForBindingFrom below?

[kochi, 2016/10/25 10:08:04]

Ah good catch! I forgot to add this logic to
Fullscreen::currentFullScreenElementForBindingFrom below.
(the layout test case didn't catch this unfortunately, as
document.adjustedElement() does also skip V0 shadow root.)

+    // shadow tree, even though it leaks the Shadow DOM.
+    if (element->isInV0ShadowTree()) {
+      UseCounter::count(scope.document(),
+                        UseCounter::DocumentFullscreenElementInV0Shadow);
+      return element;
+    }
+  } else {
+    if (!toShadowRoot(scope).isV1())
+      return nullptr;
+  }
+  return scope.adjustedElement(*element);
+}
+
 Element* Fullscreen::currentFullScreenElementFrom(Document& document) {
   if (Fullscreen* found = fromIfExists(document))
     return found->currentFullScreenElement();
   return nullptr;
 }
 
+Element* Fullscreen::currentFullScreenElementForBindingFrom(
+    Document& document) {
+  Element* element = currentFullScreenElementFrom(document);
+  if (!element || !RuntimeEnabledFeatures::fullscreenUnprefixedEnabled())
+    return element;
+  return document.adjustedElement(*element);
+}
+
 Fullscreen::Fullscreen(Document& document)
     : ContextLifecycleObserver(&document),
       m_fullScreenLayoutObject(nullptr),
       m_eventQueueTimer(this, &Fullscreen::eventQueueTimerFired),
       m_forCrossProcessDescendant(false) {
   document.setHasFullscreenSupplement();
 }
 
 Fullscreen::~Fullscreen() {}
 
@@ skipping 496 matching lines @@
 
 DEFINE_TRACE(Fullscreen) {
   visitor->trace(m_currentFullScreenElement);
   visitor->trace(m_fullscreenElementStack);
   visitor->trace(m_eventQueue);
   Supplement<Document>::trace(visitor);
   ContextLifecycleObserver::trace(visitor);
 }
 
 }  // namespace blink