Implement MediaSession (metadata) per frame [NOT READY, HAS DEPENDENCY]

third_party/WebKit/Source/modules/mediasession/NavigatorMediaSession.cpp

Index: third_party/WebKit/Source/modules/mediasession/NavigatorMediaSession.cpp
diff --git a/third_party/WebKit/Source/modules/mediasession/NavigatorMediaSession.cpp b/third_party/WebKit/Source/modules/mediasession/NavigatorMediaSession.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..6fbbbe21ac222ea943d4054ec63e0d84b3049ac7
--- /dev/null
+++ b/third_party/WebKit/Source/modules/mediasession/NavigatorMediaSession.cpp
@@ -0,0 +1,43 @@
+#include "modules/mediasession/NavigatorMediaSession.h"

[whywhat, 2016/09/13 16:23:26]

nit: copyright chromium authors yadayada

[Zhiqiang Zhang (Slow), 2016/09/13 18:51:52]

Done.

+
+#include "bindings/core/v8/ExceptionStatePlaceholder.h"
+#include "modules/mediasession/MediaSession.h"
+#include "platform/Supplementable.h"
+
+namespace blink {
+
+NavigatorMediaSession::NavigatorMediaSession(Navigator& navigator)
+    : DOMWindowProperty(navigator.frame())
+{
+    if (!frame())
+        return;
+    m_session = MediaSession::create(frame(), IGNORE_EXCEPTION);
+}
+
+DEFINE_TRACE(NavigatorMediaSession)
+{
+    visitor->trace(m_session);
+    Supplement<Navigator>::trace(visitor);
+    DOMWindowProperty::trace(visitor);
+}
+
+const char* NavigatorMediaSession::supplementName()
+{
+    return "NavigatorMediaSession";
+}
+
+NavigatorMediaSession& NavigatorMediaSession::from(Navigator& navigator)
+{
+    NavigatorMediaSession* supplement = static_cast<NavigatorMediaSession*>(Supplement<Navigator>::from(navigator, supplementName()));
+    if (!supplement) {
+        supplement = new NavigatorMediaSession(navigator);
+        provideTo(navigator, supplementName(), supplement);
+    }
+    return *supplement;
+}
+
+MediaSession* NavigatorMediaSession::mediaSession(Navigator& navigator)
+{
+    return NavigatorMediaSession::from(navigator).m_session.get();
+}
+}