Move Document.fullscreenElement to DocumentOrShadowRoot

third_party/WebKit/Source/core/dom/DocumentOrShadowRoot.h

 // Copyright 2016 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 DocumentOrShadowRoot_h
 #define DocumentOrShadowRoot_h
 
 #include "core/dom/Document.h"
+#include "core/dom/Fullscreen.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/frame/UseCounter.h"
 
 namespace blink {
 
 class DocumentOrShadowRoot {
 public:
     static Element* activeElement(Document& document)
     {
         return document.activeElement();
@@ skipping 50 matching lines @@
         // 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;
         UseCounter::count(shadowRoot.document(), UseCounter::ShadowRootPointerLockElement);
         const Element* target = shadowRoot.document().pointerLockElement();
         if (!target)
             return nullptr;
         return shadowRoot.adjustedElement(*target);
     }
+
+    static Element* currentFullScreenElement(Document& document)
+    {
+        Element* element = Fullscreen::currentFullScreenElementFrom(document);
+        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);

[foolip, 2016/09/20 13:44:21]

If we go the path of gating the change in behavior on FullscreenUnprefixed, then
I think the use counter won't be necessary.

[kochi, 2016/10/07 14:26:42]

Done.

+            return element;
+        }
+        return document.adjustedElement(*element);
+    }
+
+    static Element* currentFullScreenElement(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;
+
+        Element* element = Fullscreen::currentFullScreenElementFrom(shadowRoot.document());
+        return element ? shadowRoot.adjustedElement(*element) : nullptr;
+    }
+
+    static Element* fullscreenElement(Document& document)
+    {
+        Element* element = Fullscreen::fullscreenElementFrom(document);
+        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);
+    }
+
+    static Element* fullscreenElement(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;
+
+        Element* element = Fullscreen::fullscreenElementFrom(shadowRoot.document());
+        return element ? shadowRoot.adjustedElement(*element) : nullptr;
+    }
 };
 
 } // namespace blink
 
 #endif // DocumentOrShadowRoot_h