NOT FOR LANDING Implement WebMediaSession

content/browser/android/web_contents_observer_proxy.cc

 // Copyright 2015 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/android/web_contents_observer_proxy.h"
 
 #include <string>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
@@ skipping 275 matching lines @@
   Java_WebContentsObserverProxy_didStartNavigationToPendingEntry(
       env, obj.obj(), jstring_url.obj());
 }
 
 void WebContentsObserverProxy::MediaSessionStateChanged(bool is_controllable,
                                                         bool is_suspended) {
   JNIEnv* env = AttachCurrentThread();
 
   ScopedJavaLocalRef<jobject> obj(java_observer_);
 
+  // TODO(philipj): This is where we cross from content/ to chrome/, i.e. where
+  // Chrome and Opera will have different UIs. Need to send all relevant
+  // information here, i.e. the metadata for Blink-created media sessions, and
+  // the tab title and other information for the default media session.

[mlamouri (slow - plz ping), 2015/08/24 12:55:24]

tab title should be available from WebContents. I don't think we need to send
that here.

[whywhat, 2015/08/24 14:39:18]

It might make sense to send media session metadata which would be filled with
the tab title by default I guess.

[philipj_slow, 2015/08/26 07:39:48]

Right, when I wrote this comment, I was thinking that we would have a
content::MediaSession that basically just maps to Android's MediaSession, so
that it becomes the job of some other class to monitor all of the media players
in a tab and to come up with metadata since none can be provided by scripts in
this case.

However, we might consider what should happen when a script creates a
MediaSession put doesn't provide any metadata. If the fallback in this case can
be the same as for the default media session, then indeed we do not need to ever
send in a tab title at this level, it would just be the in the code that creates
the notification.

   Java_WebContentsObserverProxy_mediaSessionStateChanged(
       env, obj.obj(), is_controllable, is_suspended);
 }
 
 bool RegisterWebContentsObserverProxy(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 }  // namespace content