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..84881a44409abd5041ca389858af0b8578328a38 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 +673,14 @@ void Document::mediaQueryAffectingValueChanged()
     InspectorInstrumentation::mediaQueryResultChanged(this);
 }
 
+void Document::textTracksVisibilityChanged(bool visible)
+{
+    for (HTMLMediaElement* mediaElement = Traversal<HTMLMediaElement>::firstWithin(*this); mediaElement;

[philipj_slow, 2015/05/06 09:54:27]

There's alrady a documentToElementSetMap() in HTMLMediaElement.cpp that could be
used to avoid the traversal, see usage in HTMLMediaElement::setMediaGroup.

[srivats, 2015/06/09 00:45:51]

Done.

+        mediaElement = Traversal<HTMLMediaElement>::next(*mediaElement)) {
+        mediaElement->setClosedCaptionsVisible(visible);
+    }
+}
+
 void Document::setCompatibilityMode(CompatibilityMode mode)
 {
     if (m_compatibilityModeLocked || mode == m_compatibilityMode)