[Presentation API] Plumbing of |onstatechange| from the Mojo service to the public/platform

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 "base/logging.h"
 #include "content/browser/presentation/presentation_type_converters.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/navigation_details.h"
@@ skipping 244 matching lines @@
   availability_contexts_.erase(old_it);
   DoSetDefaultPresentationUrl(new_default_url, default_presentation_id);
 }
 
 void PresentationServiceImpl::CloseSession(
     const mojo::String& presentation_url,
     const mojo::String& presentation_id) {
   NOTIMPLEMENTED();
 }
 
+void PresentationServiceImpl::ListenForSessionStateChange(
+    const SessionStateCallback& 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 103 matching lines @@
     const NewSessionMojoCallback& callback)
     : presentation_url(presentation_url),
       presentation_id(presentation_id),
       callback(callback) {
 }
 
 PresentationServiceImpl::StartSessionRequest::~StartSessionRequest() {
 }
 
 }  // namespace content