Hook up Android closed captions 'enabled' setting to Blink

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index cb8f31309f048e6ccc3c01fc1c60d479d25a7a19..9ad5538a833e9e84263e32c81b11bdf4d8dd01b3 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -141,6 +141,7 @@
 #include "core/html/HTMLIFrameElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLLinkElement.h"
+#include "core/html/HTMLMediaElement.h"
 #include "core/html/HTMLMetaElement.h"
 #include "core/html/HTMLScriptElement.h"
 #include "core/html/HTMLStyleElement.h"
@@ -672,6 +673,30 @@ void Document::mediaQueryAffectingValueChanged()
     InspectorInstrumentation::mediaQueryResultChanged(this);
 }
 
+void Document::registerForTextTracksVisibilityChangedCallback(HTMLMediaElement* mediaElement)
+{
+    if (!mediaElement)
+        return;
+    if (m_textTracksVisibilityChangedElements.contains(mediaElement))
+        return;
+    m_textTracksVisibilityChangedElements.append(mediaElement);
+}
+
+void Document::unregisterFromTextTracksVisibilityChangedCallback(HTMLMediaElement* mediaElement)
+{
+    size_t index = m_textTracksVisibilityChangedElements.find(mediaElement);
+    if (index != kNotFound)
+        m_textTracksVisibilityChangedElements.remove(index);
+}
+
+void Document::textTracksVisibilityChanged(bool visible)
+{
+    for (Vector<HTMLMediaElement*>::iterator it = m_textTracksVisibilityChangedElements.begin();
+        it != m_textTracksVisibilityChangedElements.end(); ++it) {
+        (*it)->setClosedCaptionsVisible(visible);
+    }
+}
+
 void Document::setCompatibilityMode(CompatibilityMode mode)
 {
     if (m_compatibilityModeLocked || mode == m_compatibilityMode)