Media Session API: use MediaMetadata in the browser process.

content/common/android/media_metadata_proxy.h

Index: content/common/android/media_metadata_proxy.h
diff --git a/content/common/android/media_metadata_proxy.h b/content/common/android/media_metadata_proxy.h
new file mode 100644
index 0000000000000000000000000000000000000000..7324d4ec95b14232cba3d37b3b951f39e7d8fea5
--- /dev/null
+++ b/content/common/android/media_metadata_proxy.h
@@ -0,0 +1,29 @@
+// 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.
+
+#ifndef CONTENT_COMMON_ANDROID_MEDIA_METADATA_PROXY_H_
+#define CONTENT_COMMON_ANDROID_MEDIA_METADATA_PROXY_H_
+
+#include <jni.h>
+
+#include "base/android/scoped_java_ref.h"
+
+namespace content {
+
+struct MediaMetadata;
+
+class MediaMetadataProxy {

[Ted C, 2016/03/01 17:18:11]

The common naming would be MediaMetadataAndroid.

I also wouldn't object making MediaMetadata a class that has this method on it
defined only for Android.  Having to create this second class is somewhat sad to
me.

[mlamouri (slow - plz ping), 2016/03/16 15:47:15]

Isn't that mostly used for android implementations of a class?
The issue is that MediaMetadata is a content/public/ class so it would be
exposed to content embedders (ie. chrome/) while this proxy is only exposed to
content/. We could work around that by having MediaMetadata and
MediaMetadataImpl which is content/ only and have the CreateJavaObject() method
but that sounds like more boilerplate :)

[Ted C, 2016/03/16 16:55:58]

Nope, web_contents_android, profile_android are prime examples where the android
class is just there to expose functionality to java.

_android usage:
https://code.google.com/p/chromium/codesearch#search/&q=file:.*_android%5C.h&...

_proxy usage:
https://code.google.com/p/chromium/codesearch#search/&q=file:.*_proxy.h%20fil...

While the _android.h is certainly muddled and can definitely mean the android
version of some class.  I still think it makes sense here more than proxy.

This isn't a proxy, it is actually just a class that creates java equivalent
versions.  MediaMetadataFactoryAndroid might be more accurate but more verbose
as well, so I still stand by that MediaMetadataAndroid is the best option for
this.

[mlamouri (slow - plz ping), 2016/03/16 20:31:54]

Ok. Done :)

+ public:
+  static base::android::ScopedJavaLocalRef<jobject> GetJavaObject(

[Ted C, 2016/03/01 17:18:11]

I would use CreateJavaObject, Get implies reuse to me

[mlamouri (slow - plz ping), 2016/03/16 15:47:15]

Done.

+      JNIEnv* env, const MediaMetadata& metadata);
+
+  static bool Register(JNIEnv* env);
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(MediaMetadataProxy);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_ANDROID_MEDIA_METADATA_PROXY_H_