Web MIDI: implement permission infobar

chrome/browser/media/chrome_midi_permission_context.h

+// 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.
+
+#ifndef CHROME_BROWSER_MEDIA_CHROME_MIDI_PERMISSION_CONTEXT_H_
+#define CHROME_BROWSER_MEDIA_CHROME_MIDI_PERMISSION_CONTEXT_H_
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/content_settings/permission_queue_controller.h"
+#include "content/public/browser/browser_context.h"
+
+class GURL;
+class PermissionRequestID;
+class Profile;
+
+// Chrome specific implementation of MIDIPermissionContext; manages MIDI

[Bernhard Bauer, 2013/07/31 15:35:39]

What's MIDIPermissionContext? It's not a superclass of this class, and I can't
find it on codesearch.

[Takashi Toyoshima, 2013/08/01 07:43:09]

Oops. Sorry, this should be removed at cleanup.
Originally, I had a MIDIPermissionContext in the content API layer, and this
implements it.
But, I decided to omit it when I took a content API review.

Sorry for bothering you. This class still contains some remains of that.

+// permissions flow, and delegates UI handling.
+class ChromeMIDIPermissionContext
+    : public base::RefCountedThreadSafe<ChromeMIDIPermissionContext> {

[Bernhard Bauer, 2013/07/31 15:35:39]

Why is this class refcounted thread safe?

[Takashi Toyoshima, 2013/08/01 07:43:09]

As we commented in the cc file, this class is used from IO thread and internally
works in UI thread.
It should be ref counted so that it works in both thread using PostTask.

+ public:
+  explicit ChromeMIDIPermissionContext(Profile* profile);
+
+  void RequestMIDISysExPermission(
+      int render_process_id,
+      int render_view_id,
+      const GURL& requesting_frame,
+      const content::BrowserContext::MIDISysExPermissionCallback& callback);
+
+  // Called on the UI thread when the profile is about to be destroyed.
+  void ShutdownOnUIThread();
+
+ protected:
+  virtual ~ChromeMIDIPermissionContext();

[Bernhard Bauer, 2013/07/31 15:35:39]

Is this class subclassed?

[Takashi Toyoshima, 2013/08/01 07:43:09]

Yes for RefCounted.

[Bernhard Bauer, 2013/08/01 08:21:27]

?

Oh, my question might have been worded ambiguously. What I meant to ask was, is
there a subclass of this class? If not, you can make the destructor private.

[Takashi Toyoshima, 2013/08/01 09:29:45]

Ah, I see. I misunderstood your question.
Done.

+
+ private:
+  Profile* profile() const { return profile_; }

[Bernhard Bauer, 2013/07/31 15:35:39]

Do you really need a private accessor? :)

[Takashi Toyoshima, 2013/08/01 07:43:09]

Good point. I remove this to use it directly :)

+
+  // Return an instance of the infobar queue controller, creating it
+  // if necessary.
+  PermissionQueueController* QueueController();

[Bernhard Bauer, 2013/07/31 15:35:39]

Nit: GetQueueController() maybe?

[Takashi Toyoshima, 2013/08/01 07:43:09]

Done.

+
+  // Called on the UI thread when the permission decision is made. It may be by
+  // the InfoBarDelegate to notify permission has been set.
+  void NotifyPermissionSet(
+      const PermissionRequestID& id,
+      const GURL& requesting_frame,
+      const content::BrowserContext::MIDISysExPermissionCallback& callback,
+      bool allowed);
+
+  // Decide whether the permission should be granted.
+  // Calls PermissionDecided if permission can be decided non-interactively,
+  // or NotifyPermissionSet if permission decided by presenting an infobar.
+  // Called on the UI thread.
+  void DecidePermission(
+      const PermissionRequestID& id,
+      const GURL& requesting_frame,
+      const GURL& embedder,
+      const content::BrowserContext::MIDISysExPermissionCallback& callback);
+
+  // Called when permission is granted without interactively asking the user.
+  // Called on the UI thread.
+  void PermissionDecided(
+      const PermissionRequestID& id,
+      const GURL& requesting_frame,
+      const GURL& embedder,
+      const content::BrowserContext::MIDISysExPermissionCallback& callback,
+      bool allowed);
+
+  // Create an PermissionQueueController. overriden in derived classes to

[Bernhard Bauer, 2013/07/31 15:35:39]

Nit: "Overridden". Also, are these derived classes still forthcoming?

[Takashi Toyoshima, 2013/08/01 07:43:09]

Oops. This also may not happen now, so I'll remove the virtual.

+  // provide additional UI flow.  Called on the UI thread.
+  virtual PermissionQueueController* CreateQueueController();
+
+  Profile* const profile_;
+  bool shutting_down_;
+  scoped_ptr<PermissionQueueController> permission_queue_controller_;
+
+  friend class base::RefCountedThreadSafe<ChromeMIDIPermissionContext>;

[Bernhard Bauer, 2013/07/31 15:35:39]

Friend declarations come first in the private part.

[Takashi Toyoshima, 2013/08/01 07:43:09]

Done.

+};
+
+#endif  // CHROME_BROWSER_MEDIA_CHROME_MIDI_PERMISSION_CONTEXT_H_