[PresentationAPI] Implementing send() from WebPresentationClient to the PresentationService.

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 "base/callback.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/presentation_session.h"
@@ skipping 13 matching lines @@
     virtual void OnDelegateDestroyed() = 0;
 
    protected:
     virtual ~Observer() {}
   };
 
   using PresentationSessionSuccessCallback =
       base::Callback<void(const PresentationSessionInfo&)>;
   using PresentationSessionErrorCallback =
       base::Callback<void(const PresentationError&)>;
+  using SendMessageCallback = base::Callback<void()>;
 
   virtual ~PresentationServiceDelegate() {}
 
   // 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;
 
@@ skipping 64 matching lines @@
   // |success_cb|: Invoked with session info, if presentation session joined
   // successfully.
   // |error_cb|: Invoked with error reason, if joining failed.
   virtual void JoinSession(
       int render_process_id,
       int render_frame_id,
       const std::string& presentation_url,
       const std::string& presentation_id,
       const PresentationSessionSuccessCallback& success_cb,
       const PresentationSessionErrorCallback& error_cb) = 0;
+
+  // Sends a string message to a presentation session.
+  // |render_process_id|, |render_frame_id|: ID of originating frame.
+  // |presentation_url|: URL of the presentation.
+  // |presentation_id|: ID of the presentation.
+  // |message|: message to be sent.
+  // |send_message_cb|: Invoked when message is sent.
+  virtual void SendStringMessage(
+      int render_process_id,
+      int render_frame_id,
+      const std::string& presentation_url,
+      const std::string& presentation_id,
+      const std::string& message,
+      const SendMessageCallback& send_message_cb) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_