Web MIDI: use midi_service.mojom for media::midi::Result

media/midi/midi_service.mojom

+// Copyright 2016 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.
+
+module media.midi;

[Reilly Grant (use Gerrit), 2016/10/11 17:57:57]

Convention is to put mojo definitions into a namespace called "mojom" which is a
rare exception to the convention that we don't generally nest namespaces. So
this module should probably be either "midi.mojom", or "media.mojom" with types
renamed to start with "Midi".

[Takashi Toyoshima, 2016/10/12 05:01:44]

Thanks. So, probably midi.mojom looks better rather than media because midi is
historically placed in media, but it doesn't depend on media, and now we can
build it as a separate component. I thought eventually we would use top midi
namespace instead of media.midi in C++ world. So, I'd switch it now.

+
+enum Result {
+  NOT_INITIALIZED,
+  OK,
+  NOT_SUPPORTED,
+  INITIALIZATION_ERROR,
+
+  // New code should be inserted here so that existing members keep the same
+  // assigned value. //tools/metrics/histograms/histograms.xml contains a enum
+  // entry that should be consistent with enum Result.
+
+  // |MAX| is used in content/common/media/midi_messages.h with
+  // IPC_ENUM_TRAITS_MAX_VALUE macro. Keep the value up to date. Otherwise
+  // a new value can not be passed to the renderer.
+  // TODO(toyoshim): Remove |MAX| once IPC is replaced with Mojo.
+  // http://crbug.com/582327
+  MAX = INITIALIZATION_ERROR,
+};
+
+// TODO(toyoshim): MidiPortState, MidiPortInfo, and MidiService should be
+// declared here.
+// http://crbug.com/582327