Move Document.fullscreenElement to DocumentOrShadowRoot

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

Index: third_party/WebKit/Source/core/dom/Fullscreen.cpp
diff --git a/third_party/WebKit/Source/core/dom/Fullscreen.cpp b/third_party/WebKit/Source/core/dom/Fullscreen.cpp
index f30793ebf893232c84067a756b252a75473c91a3..e75d853d744c37555a2ba3a42a12fd70c8c74e20 100644
--- a/third_party/WebKit/Source/core/dom/Fullscreen.cpp
+++ b/third_party/WebKit/Source/core/dom/Fullscreen.cpp
@@ -218,6 +218,39 @@ Element* Fullscreen::currentFullScreenElementFrom(Document& document) {
   return nullptr;
 }
 
+Element* Fullscreen::fullscreenElementForBindingFrom(Document& document) {
+  Element* element = nullptr;
+  if (Fullscreen* found = fromIfExists(document))
+    element = found->fullscreenElement();
+  if (!element)
+    return nullptr;
+
+  // For Shadow DOM V0 compatibility: We allow returning an element in V0
+  // shadow tree, even though it leaks the Shadow DOM.
+  // TODO(kochi): Once V0 code is removed, the following V0 check is
+  // unnecessary.
+  if (element->isInV0ShadowTree()) {
+    UseCounter::count(document,
+                      UseCounter::DocumentFullscreenElementInV0Shadow);
+    return element;
+  }
+  return document.adjustedElement(*element);
+}
+
+Element* Fullscreen::fullscreenElementForBindingFrom(ShadowRoot& shadowRoot) {
+  // TODO(kochi): Once V0 code is removed, the following non-V1 check is
+  // unnecessary. After V0 code is removed, we can use the same logic for
+  // Document and ShadowRoot.
+  if (!shadowRoot.isV1())
+    return nullptr;
+
+  if (Fullscreen* found = fromIfExists(shadowRoot.document())) {
+    if (Element* element = found->fullscreenElement())
+      return shadowRoot.adjustedElement(*element);
+  }
+  return nullptr;
+}
+
 Fullscreen::Fullscreen(Document& document)
     : ContextLifecycleObserver(&document),
       m_fullScreenLayoutObject(nullptr),