[Presentation API] Change ListenForSessionMessages API to client-style.

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_
 
 #include <vector>
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/presentation_session.h"
 #include "content/public/browser/presentation_session_message.h"
 
 namespace content {
 
 class PresentationScreenAvailabilityListener;
 
 using SessionStateChangedCallback =
     base::Callback<void(const PresentationSessionInfo&,
                         PresentationSessionState)>;
+using PresentationSessionMessageCallback = base::Callback<void(
+    const ScopedVector<content::PresentationSessionMessage>&)>;
 
 // An interface implemented by embedders to handle presentation API calls
 // forwarded from PresentationServiceImpl.
 class CONTENT_EXPORT PresentationServiceDelegate {
  public:
   // Observer interface to listen for changes to PresentationServiceDelegate.
   class CONTENT_EXPORT Observer {
    public:
     // Called when the PresentationServiceDelegate is being destroyed.
     virtual void OnDelegateDestroyed() = 0;
 
     // Called when the default presentation has been started outside of a
     // Presentation API context (e.g., browser action). This will not be called
     // if the session was created as a result of Presentation API's
     // StartSession()/JoinSession().
     virtual void OnDefaultPresentationStarted(
         const PresentationSessionInfo& session) = 0;
 
    protected:
     virtual ~Observer() {}
   };
 
   using PresentationSessionSuccessCallback =
       base::Callback<void(const PresentationSessionInfo&)>;
   using PresentationSessionErrorCallback =
       base::Callback<void(const PresentationError&)>;
-  using PresentationSessionMessageCallback = base::Callback<void(
-      scoped_ptr<ScopedVector<PresentationSessionMessage>>)>;
   using SendMessageCallback = base::Callback<void(bool)>;
 
   virtual ~PresentationServiceDelegate() {}
 
   // Registers an observer associated with frame with |render_process_id|
   // and |render_frame_id| with this class to listen for updates.
   // This class does not own the observer.
   // It is an error to add an observer if there is already an observer for that
   // frame.
   virtual void AddObserver(int render_process_id,
@@ skipping 75 matching lines @@
       const PresentationSessionSuccessCallback& success_cb,
       const PresentationSessionErrorCallback& error_cb) = 0;
 
   // Close an existing presentation session.
   // |render_process_id|, |render_frame_id|: ID for originating frame.
   // |presentation_id|: The ID of the presentation to close.
   virtual void CloseSession(int render_process_id,
                             int render_frame_id,
                             const std::string& presentation_id) = 0;
 
-  // Gets the next batch of messages from all presentation sessions in the frame
+  // Listen for messages for a presentation session.
   // |render_process_id|, |render_frame_id|: ID for originating frame.
-  // |message_cb|: Invoked with a non-empty list of messages.
+  // |session|: URL and ID of presentation session to listen for messages.
+  // |message_cb|: Invoked with a non-empty list of messages whenever there are
+  // messages.
   virtual void ListenForSessionMessages(
       int render_process_id,
       int render_frame_id,
+      const content::PresentationSessionInfo& session,
       const PresentationSessionMessageCallback& message_cb) = 0;
 
   // Sends a message (string or binary data) to a presentation session.
   // |render_process_id|, |render_frame_id|: ID of originating frame.
-  // |message_request|: Contains Presentation URL, ID and message to be sent
-  // and delegate is responsible for deallocating the message_request.
+  // |session|: The presentation session to send the message to.
+  // |message|: The message to send. The embedder takes ownership of |message|.
+  //            Must not be null.
   // |send_message_cb|: Invoked after handling the send message request.
-  virtual void SendMessage(
-      int render_process_id,
-      int render_frame_id,
-      scoped_ptr<PresentationSessionMessage> message_request,
-      const SendMessageCallback& send_message_cb) = 0;
+  virtual void SendMessage(int render_process_id,
+                           int render_frame_id,
+                           const content::PresentationSessionInfo& session,
+                           scoped_ptr<PresentationSessionMessage> message,
+                           const SendMessageCallback& send_message_cb) = 0;
 
   // Continuously listen for presentation session state changes for a frame.
   // |render_process_id|, |render_frame_id|: ID of frame.
   // |state_changed_cb|: Invoked with the session and its new state whenever
   // there is a state change.
   virtual void ListenForSessionStateChange(
       int render_process_id,
       int render_frame_id,
       const SessionStateChangedCallback& state_changed_cb) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_