Presentation API: ignore presentation id passed to startSession().

chrome/browser/media/router/presentation_service_delegate_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 "chrome/browser/media/router/presentation_service_delegate_impl.h"
 
 #include <string>
 
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/containers/small_map.h"
@@ skipping 530 matching lines @@
   frame_manager_->OnPresentationSessionStarted(
       RenderFrameHostId(render_process_id, render_frame_id), false, new_session,
       route_id);
   success_cb.Run(new_session);
 }
 
 void PresentationServiceDelegateImpl::StartSession(
     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) {
   if (presentation_url.empty() || !IsValidPresentationUrl(presentation_url)) {
     error_cb.Run(content::PresentationError(content::PRESENTATION_ERROR_UNKNOWN,
                                             "Invalid presentation arguments."));
     return;
   }
   RenderFrameHostId render_frame_host_id(render_process_id, render_frame_id);
-  std::string final_presentation_id =
-      presentation_id.empty()
-          ? frame_manager_->GetDefaultPresentationId(render_frame_host_id)
-          : presentation_id;
-  if (final_presentation_id.empty())
-    // TODO(imcheng): Remove presentation_id argument entirely if required
-    // by Presentation API spec.
-    final_presentation_id = base::GenerateGUID();
+
+  std::string presentation_id =

[mark a. foltz, 2015/07/06 21:00:57]

The code path to retrieve the default presentation ID from the frame should also
be removed.

However, since this API is going to be changing anyway, it might be cleaner to
do it in a separate patch that implements the new API.

So, ignoring the frame-provided presentation ID, and adding a TODO would be fine
as well.

[mlamouri (slow - plz ping), 2015/07/08 14:37:09]

I will keep it as-is and add a TODO saying that we will remove it.

+      frame_manager_->GetDefaultPresentationId(render_frame_host_id);
+  if (presentation_id.empty())
+    presentation_id = base::GenerateGUID();
+
   scoped_ptr<CreateSessionRequest> context(new CreateSessionRequest(
-      presentation_url, final_presentation_id,
+      presentation_url, presentation_id,
       GetLastCommittedURLForFrame(render_frame_host_id),
       base::Bind(&PresentationServiceDelegateImpl::OnStartSessionSucceeded,
                  weak_factory_.GetWeakPtr(), render_process_id, render_frame_id,
                  success_cb),
       error_cb));
   // NOTE: Currently this request is ignored if a dialog is already open, e.g.
   // via browser action. In practice, this should rarely happen, but log
   // an error message in case it does.
   MediaRouterDialogController::CreateForWebContents(web_contents_);
   MediaRouterDialogController* controller =
@@ skipping 119 matching lines @@
 bool PresentationServiceDelegateImpl::HasScreenAvailabilityListenerForTest(
     int render_process_id,
     int render_frame_id,
     const MediaSource::Id& source_id) const {
   RenderFrameHostId render_frame_host_id(render_process_id, render_frame_id);
   return frame_manager_->HasScreenAvailabilityListenerForTest(
       render_frame_host_id, source_id);
 }
 
 }  // namespace media_router