Add content public APIs for Presentation API.

content/public/browser/presentation_service_delegate.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_
+#define CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_
+
+namespace content {
+
+class PresentationScreenAvailabilityListener;
+
+// An interface implemented by embedders to handle presentation API calls
+// forwarded from PresentationServiceImpl.
+class PresentationServiceDelegate {
+ public:
+  // Observer interface to listen for changes to PresentationServiceDelegate.
+  class Observer {
+   public:
+    // Called when the PresentationServiceDelegate is being destroyed.
+    virtual void OnDelegateDestroyed() = 0;
+
+   protected:
+    virtual ~Observer() {}
+  };
+
+  // Registers an observer with this class to listen for updates to this class.
+  // This class does not own the observer.
+  // It is an error to add an observer if it has already been added before.
+  virtual void AddObserver(Observer* observer) = 0;
+  // Unregisters an observer with this class.
+  virtual void RemoveObserver(Observer* observer) = 0;
+
+  // Registers |listener| to continuously listen for
+  // availability updates for a presentation URL, originated from the frame
+  // given by |render_process_id| and |render_frame_id|.
+  // This class does not own |listener|.
+  // Returns true on success.
+  // This call will return false if a listener with the same presentation URL
+  // from the same frame is already registered.
+  virtual bool AddScreenAvailabilityListener(
+      int render_process_id,
+      int render_frame_id,
+      PresentationScreenAvailabilityListener* listener) = 0;
+
+  // Unregisters |listener| originated from the frame given by
+  // |render_process_id| and |render_frame_id| from this class. The listener
+  // will no longer receive availability updates.
+  virtual void RemoveScreenAvailabilityListener(
+      int render_process_id,
+      int render_frame_id,
+      PresentationScreenAvailabilityListener* listener) = 0;
+
+  // Unregisters all listeners associated with the frame given by
+  // |render_process_id| and |render_frame_id|.
+  virtual void RemoveAllScreenAvailabilityListeners(
+      int render_process_id,
+      int render_frame_id) = 0;
+
+ protected:
+  virtual ~PresentationServiceDelegate() {}
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_