Adding mojo MediaSessionClient to support media controls

third_party/WebKit/Source/modules/mediasession/MediaSession.h

Index: third_party/WebKit/Source/modules/mediasession/MediaSession.h
diff --git a/third_party/WebKit/Source/modules/mediasession/MediaSession.h b/third_party/WebKit/Source/modules/mediasession/MediaSession.h
index 004edd1c01126ff8098dfcbe37db8591e485603a..888e06816b7bc42a60288af8ca279048ce5b6c28 100644
--- a/third_party/WebKit/Source/modules/mediasession/MediaSession.h
+++ b/third_party/WebKit/Source/modules/mediasession/MediaSession.h
@@ -8,6 +8,7 @@
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/events/EventTarget.h"
 #include "modules/ModulesExport.h"
+#include "mojo/public/cpp/bindings/binding.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/modules/mediasession/media_session.mojom-blink.h"
 #include <memory>
@@ -17,7 +18,9 @@ namespace blink {
 class MediaMetadata;
 class ScriptState;
 
-class MODULES_EXPORT MediaSession final : public EventTargetWithInlineData {
+class MODULES_EXPORT MediaSession final
+    : public EventTargetWithInlineData,
+      blink::mojom::blink::MediaSessionClient {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
@@ -55,12 +58,16 @@ class MODULES_EXPORT MediaSession final : public EventTargetWithInlineData {
 
   MediaSession(ScriptState*);
 
+  // blink::mojom::blink::MediaSessionClient implementation.
+  void DidReceivedAction(const WTF::String& action) override;
+
   // Returns null when the ExecutionContext is not document.
   mojom::blink::MediaSessionService* getService(ScriptState*);
 
   RefPtr<ScriptState> m_scriptState;
   Member<MediaMetadata> m_metadata;
   mojom::blink::MediaSessionServicePtr m_service;
+  mojo::Binding<blink::mojom::blink::MediaSessionClient> m_clientBinding;
 };
 
 }  // namespace blink