[Presentation API] Convert screen availability API into Client style.

content/renderer/presentation/presentation_dispatcher.h

Index: content/renderer/presentation/presentation_dispatcher.h
diff --git a/content/renderer/presentation/presentation_dispatcher.h b/content/renderer/presentation/presentation_dispatcher.h
index c88786357c747663c30d61b430e55fa311084f94..6bf980a3806e2ba21e92ed16604e4e8a7ddd7010 100644
--- a/content/renderer/presentation/presentation_dispatcher.h
+++ b/content/renderer/presentation/presentation_dispatcher.h
@@ -21,7 +21,8 @@ namespace content {
 // Blink. It forwards the calls to the Mojo PresentationService.
 class CONTENT_EXPORT PresentationDispatcher
     : public RenderFrameObserver,
-      public NON_EXPORTED_BASE(blink::WebPresentationClient) {
+      public NON_EXPORTED_BASE(blink::WebPresentationClient),
+      public NON_EXPORTED_BASE(presentation::PresentationServiceClient) {
  public:
   explicit PresentationDispatcher(RenderFrame* render_frame);
   ~PresentationDispatcher() override;
@@ -46,9 +47,9 @@ class CONTENT_EXPORT PresentationDispatcher
   // RenderFrameObserver
   void DidChangeDefaultPresentation() override;
 
-  void OnScreenAvailabilityChanged(
-      const std::string& presentation_url,
-      bool available);
+  // presentation::PresentationServiceClient
+  void OnScreenAvailabilityUpdated(bool available) override;
+
   void OnSessionCreated(
       blink::WebPresentationSessionClientCallbacks* callback,
       presentation::PresentationSessionInfoPtr session_info,
@@ -63,13 +64,10 @@ class CONTENT_EXPORT PresentationDispatcher
 
   void ConnectToPresentationServiceIfNeeded();
 
-  void DoUpdateAvailableChangeWatched(
-      const std::string& presentation_url,
-      bool watched);
-
   // Used as a weak reference. Can be null since lifetime is bound to the frame.
   blink::WebPresentationController* controller_;
   presentation::PresentationServicePtr presentation_service_;
+  mojo::Binding<presentation::PresentationServiceClient> binding_;
 };
 
 }  // namespace content