[Presentation API] (MR side) 1-UA: notify receiver page when receiver connection becomes available

content/public/browser/presentation_service_delegate.h

Index: content/public/browser/presentation_service_delegate.h
diff --git a/content/public/browser/presentation_service_delegate.h b/content/public/browser/presentation_service_delegate.h
index cbe2c5f1cc9c5c64cbc46d32beb5b1cca81c4950..1d271bda6143948d3ec77f5465882477fe0969ad 100644
--- a/content/public/browser/presentation_service_delegate.h
+++ b/content/public/browser/presentation_service_delegate.h
@@ -47,6 +47,28 @@ struct PresentationConnectionStateChangeInfo {
 using PresentationConnectionStateChangedCallback =
     base::Callback<void(const PresentationConnectionStateChangeInfo&)>;
 
+// This class serves as a proxy to PSImpl.
+class OffscreenPresentationClient {
+ public:
+  OffscreenPresentationClient() {}
+  // Called when 1. receiver page is rendered for a presentation;
+  //             2. new controller is connected to the presentation.
+  virtual void OnReceiverConnectionAvailable(
+      const content::PresentationSessionInfo&) = 0;
+  // For controller, add a receiver client to its observer list, and the list
+  // contains at most one element;
+  // For receiver, add a controller client to its observer list, and the list
+  // may contain multiple elements.
+  virtual void AddOffscreenPresentationObserver(
+      OffscreenPresentationClient*) = 0;
+
+  virtual void RemoveOffscreenPresentationObserver(
+      OffscreenPresentationClient*) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(OffscreenPresentationClient);
+};
+
 // An interface implemented by embedders to handle presentation API calls
 // forwarded from PresentationServiceImpl.
 class CONTENT_EXPORT PresentationServiceDelegate {
@@ -203,6 +225,24 @@ class CONTENT_EXPORT PresentationServiceDelegate {
       int render_frame_id,
       const PresentationSessionInfo& connection,
       const PresentationConnectionStateChangedCallback& state_changed_cb) = 0;
+
+  // Called when receiver PSImpl is connected with receiver render process.
+  virtual void RegisterOffscreenPresentationReceiver(
+      OffscreenPresentationClient*) = 0;
+
+  // Called when receiver frame is destroyed.
+  virtual void UnregisterOffscreenPresentationReceiver(
+      OffscreenPresentationClient*) = 0;
+
+  // Called when successfully starting presentation session.
+  virtual void RegisterOffscreenPresentationController(
+      const std::string& presentationId,
+      OffscreenPresentationClient*) = 0;
+
+  // Called when presentation connection is closed.
+  virtual void UnregisterOffscreenPresentationController(
+      const std::string& presentationId,
+      OffscreenPresentationClient*) = 0;
 };
 
 }  // namespace content