Presentation API: cleanup leftovers from .getAvailability() changes.

public/platform/modules/presentation/WebPresentationController.h

Index: public/platform/modules/presentation/WebPresentationController.h
diff --git a/public/platform/modules/presentation/WebPresentationController.h b/public/platform/modules/presentation/WebPresentationController.h
index a539e577ae9126a9446c70122995789c9c7a03de..a7c8695fee96891aae8cbb1b9dfd8536daf24b3b 100644
--- a/public/platform/modules/presentation/WebPresentationController.h
+++ b/public/platform/modules/presentation/WebPresentationController.h
@@ -18,13 +18,6 @@ class BLINK_PLATFORM_EXPORT WebPresentationController {
 public:
     virtual ~WebPresentationController() { }
 
-    // Called when the presentation screen availability changes.
-    // May not be called if there's no registered listener for the event.
-    virtual void didChangeAvailability(bool available) = 0;
-
-    // Indicates if the frame has listeners to the |availablechange| event.
-    virtual bool isAvailableChangeWatched() const = 0;
-
     // Called when the presentation session is started by the embedder using
     // the default presentation URL and id.
     virtual void didStartDefaultSession(WebPresentationSessionClient*) = 0;