Support subtitles for native fullscreen video

Source/core/dom/Element.cpp

Index: Source/core/dom/Element.cpp
diff --git a/Source/core/dom/Element.cpp b/Source/core/dom/Element.cpp
index 38e67b70942a40af6a4ace09322dac6b4ff272d8..15815152c932421979264a3cf28e05d414080a21 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -1353,6 +1353,12 @@ void Element::attach(const AttachContext& context)
     }
 
     InspectorInstrumentation::didRecalculateStyleForElement(this);
+
+    if (FullscreenElementStack::isActiveFullScreenElement(this)) {
+        RenderView* view = document().topDocument()->renderView();
+        ASSERT(view);
+        view->setCurrentFullscreenRenderer(renderer());
+    }
 }
 
 void Element::unregisterNamedFlowContentNode()
@@ -1363,6 +1369,12 @@ void Element::unregisterNamedFlowContentNode()
 
 void Element::detach(const AttachContext& context)
 {
+    if (FullscreenElementStack::isActiveFullScreenElement(this)) {
+        RenderView* view = document().topDocument()->renderView();
+        if (view)
+            view->setCurrentFullscreenRenderer(0);
+    }
+
     WidgetHierarchyUpdatesSuspensionScope suspendWidgetHierarchyUpdates;
     unregisterNamedFlowContentNode();
     cancelFocusAppearanceUpdate();
@@ -3648,4 +3660,18 @@ Attribute* UniqueElementData::attributeItem(unsigned index)
     return &m_attributeVector.at(index);
 }
 
+void Element::didBecomeFullscreenElement()
+{
+    RenderView* view = document().topDocument()->renderView();
+    ASSERT(view);
+    view->setCurrentFullscreenRenderer(renderer());
+}
+
+void Element::willStopBeingFullscreenElement()
+{
+    RenderView* view = document().topDocument()->renderView();
+    ASSERT(view);
+    view->setCurrentFullscreenRenderer(0);
+}
+
 } // namespace WebCore