Migrating MediaSession messages to mojo

third_party/WebKit/public/platform/modules/mediasession/media_session.mojom

Index: third_party/WebKit/public/platform/modules/mediasession/media_session.mojom
diff --git a/third_party/WebKit/public/platform/modules/mediasession/media_session.mojom b/third_party/WebKit/public/platform/modules/mediasession/media_session.mojom
new file mode 100644
index 0000000000000000000000000000000000000000..2800e17b99596d91ebfa7570e44ccc528db4c229
--- /dev/null
+++ b/third_party/WebKit/public/platform/modules/mediasession/media_session.mojom
@@ -0,0 +1,26 @@
+// 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 blink.mojom;
+
+import "mojo/common/common_custom_types.mojom";
+import "ui/gfx/geometry/mojo/geometry.mojom";
+import "url/mojo/url.mojom";
+
+struct MediaMetadataIcon {

[xhwang, 2016/09/30 23:24:58]

Please add comments to new interfaces. It's very hard for other developers not
familiar with this code (like me) to understand what is going on.

[Zhiqiang Zhang (Slow), 2016/10/03 14:31:13]

Done.

+  url.mojom.Url src;
+  mojo.common.mojom.String16 type;
+  array<gfx.mojom.Size> sizes;
+};
+
+struct MediaMetadata {
+  mojo.common.mojom.String16 title;
+  mojo.common.mojom.String16 artist;
+  mojo.common.mojom.String16 album;
+  array<MediaMetadataIcon> artwork;
+};
+
+interface MediaSessionService {

[xhwang, 2016/09/30 23:24:58]

nit: Do you really need the "Service" part? We used to call mojo interface
implementations "service". Then "service" has a special meaning in the mojo
world [1]. We used to have some mojo interfaces called *Service but I don't find
that adds too much value.

[1]
https://cs.chromium.org/chromium/src/services/shell/public/cpp/service.h?rcl=...

[Zhiqiang Zhang (Slow), 2016/10/03 14:31:13]

Done. The sad thing is that we have too many classes named "MediaSession" which
I was trying to avoid.

+  SetMetadata(MediaMetadata? metadata);
+};