[PresentationAPI] Added on-session-message handler.

content/browser/presentation/presentation_service_impl.cc

 // 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.
 
 #include "content/browser/presentation/presentation_service_impl.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "content/browser/presentation/presentation_type_converters.h"
@@ skipping 307 matching lines @@
     const mojo::String& presentation_url,
     const mojo::String& presentation_id) {
   NOTIMPLEMENTED();
 }
 
 void PresentationServiceImpl::ListenForSessionStateChange(
     const SessionStateCallback& callback) {
   NOTIMPLEMENTED();
 }
 
+void PresentationServiceImpl::ListenForSessionTextMessage(
+    const SessionTextMessageCallback& callback) {
+  NOTIMPLEMENTED();
+}
+
 void PresentationServiceImpl::DidNavigateAnyFrame(
     content::RenderFrameHost* render_frame_host,
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
   DVLOG(2) << "PresentationServiceImpl::DidNavigateAnyFrame";
   if (render_frame_host_ != render_frame_host)
     return;
 
   std::string prev_url_host = details.previous_url.host();
   std::string curr_url_host = params.url.host();
@@ skipping 135 matching lines @@
 
 PresentationServiceImpl::NewSessionMojoCallback
 PresentationServiceImpl::StartSessionRequest::PassCallback() {
   NewSessionMojoCallback callback = callback_;
   callback_.reset();
   return callback;
 }
 
 }  // namespace content