Web MIDI: implement permission infobar

content/browser/renderer_host/media/midi_dispatcher_host.cc

 // Copyright 2013 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/renderer_host/media/midi_dispatcher_host.h"
 
 #include "base/bind.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/common/media/midi_messages.h"
 #include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
 #include "url/gurl.h"
 
 namespace content {
 
 MIDIDispatcherHost::MIDIDispatcherHost(int render_process_id,
                                        BrowserContext* browser_context)
     : render_process_id_(render_process_id),
       browser_context_(browser_context) {
 }
 
 MIDIDispatcherHost::~MIDIDispatcherHost() {
 }
 
 bool MIDIDispatcherHost::OnMessageReceived(const IPC::Message& message,
                                            bool* message_was_ok) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP_EX(MIDIDispatcherHost, message, *message_was_ok)
     IPC_MESSAGE_HANDLER(MIDIHostMsg_RequestSysExPermission,
                         OnRequestSysExPermission)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
   return handled;
 }
 
+void MIDIDispatcherHost::OverrideThreadForMessage(
+    const IPC::Message& message, BrowserThread::ID* thread) {
+  if (message.type() == MIDIHostMsg_RequestSysExPermission::ID)
+    *thread = BrowserThread::UI;
+}
+
 void MIDIDispatcherHost::OnRequestSysExPermission(int render_view_id,
                                                   int client_id,
                                                   const GURL& origin) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
   browser_context_->RequestMIDISysExPermission(
       render_process_id_,
       render_view_id,
       origin,
       base::Bind(&MIDIDispatcherHost::WasSysExPermissionGranted,
                  base::Unretained(this),
                  render_view_id,
                  client_id));
 }
 
 void MIDIDispatcherHost::WasSysExPermissionGranted(int render_view_id,
                                                    int client_id,
                                                    bool success) {
   RenderViewHostImpl* r =
       RenderViewHostImpl::FromID(render_process_id_, render_view_id);

[Bernhard Bauer, 2013/08/01 15:28:41]

I don't think getting the RenderViewHostImpl is necessary here; you could just
directly call Send().

[Takashi Toyoshima, 2013/08/01 15:36:26]

I did like this because the message couldn't be routed to the right renderer
when I call Send().

[Bernhard Bauer, 2013/08/01 22:24:33]

As in, to the right render process? I thought this object belongs to a single
process (which is the one identified by render_process_id_)?

   if (!r)
     return;
   r->Send(
       new MIDIMsg_SysExPermissionApproved(render_view_id, client_id, success));
 }
 
 }  // namespace content