Make MediaSession a runtime-enabled feature on Desktop.

content/public/android/java/src/org/chromium/content/browser/MediaSessionDelegate.java

Index: content/public/android/java/src/org/chromium/content/browser/MediaSessionDelegate.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/MediaSession.java b/content/public/android/java/src/org/chromium/content/browser/MediaSessionDelegate.java
similarity index 53%
rename from content/public/android/java/src/org/chromium/content/browser/MediaSession.java
rename to content/public/android/java/src/org/chromium/content/browser/MediaSessionDelegate.java
index 6723de74e8429d215b7db66138fc6844f2122bf0..df16ecb84d589596289ce239baf0588b8415e466 100644
--- a/content/public/android/java/src/org/chromium/content/browser/MediaSession.java
+++ b/content/public/android/java/src/org/chromium/content/browser/MediaSessionDelegate.java
@@ -12,18 +12,19 @@ import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 
 /**
- * MediaSession is the Java counterpart of content::MediaSession.
- * It is being used to communicate from content::MediaSession (C++) to the
- * Android system. A MediaSession is implementing OnAudioFocusChangeListener,
- * making it an audio focus holder for Android. Thus two instances of
- * MediaSession can't have audio focus at the same time.
- * A MediaSession will use the type requested from its C++ counterpart and will
- * resume its play using the same type if it were to happen, for example, when
- * it got temporarily suspended by a transient sound like a notification.
+ * MediaSession is the Java counterpart of content::MediaSessionDelegateAndroid.
+ * It is being used to communicate from content::MediaSessionDelegateAndroid
+ * (C++) to the Android system. A MediaSessionDelegate is implementingf
+ * OnAudioFocusChangeListener, making it an audio focus holder for Android. Thus
+ * two instances of MediaSessionDelegate can't have audio focus at the same
+ * time. A MediaSessionDelegate will use the type requested from its C++
+ * counterpart and will resume its play using the same type if it were to
+ * happen, for example, when it got temporarily suspended by a transient sound
+ * like a notification.
  */
 @JNINamespace("content")
-public class MediaSession implements AudioManager.OnAudioFocusChangeListener {
-    private static final String TAG = "cr.MediaSession";
+public class MediaSessionDelegate implements AudioManager.OnAudioFocusChangeListener {
+    private static final String TAG = "MediaSession";
 
     // These need to match the values in native apps.
     public static final double DUCKING_VOLUME_MULTIPLIER = 0.2f;
@@ -33,17 +34,18 @@ public class MediaSession implements AudioManager.OnAudioFocusChangeListener {
     private int mFocusType;
     private boolean mIsDucking = false;
 
-    // Native pointer to C++ content::MediaSession.
-    private final long mNativeMediaSession;
+    // Native pointer to C++ content::MediaSessionAndroid.
+    private final long mNativeMediaSessionDelegateAndroid;
 
-    private MediaSession(final Context context, long nativeMediaSession) {
+    private MediaSessionDelegate(final Context context, long nativeMediaSessionDelegateAndroid) {
         mContext = context;
-        mNativeMediaSession = nativeMediaSession;
+        mNativeMediaSessionDelegateAndroid = nativeMediaSessionDelegateAndroid;
     }
 
     @CalledByNative
-    private static MediaSession createMediaSession(Context context, long nativeMediaSession) {
-        return new MediaSession(context, nativeMediaSession);
+    private static MediaSessionDelegate create(Context context,
+                                               long nativeMediaSessionDelegateAndroid) {
+        return new MediaSessionDelegate(context, nativeMediaSessionDelegateAndroid);
     }
 
     @CalledByNative
@@ -71,23 +73,25 @@ public class MediaSession implements AudioManager.OnAudioFocusChangeListener {
         switch (focusChange) {
             case AudioManager.AUDIOFOCUS_GAIN:
                 if (mIsDucking) {
-                    nativeOnSetVolumeMultiplier(mNativeMediaSession, DEFAULT_VOLUME_MULTIPLIER);
+                    nativeOnSetVolumeMultiplier(mNativeMediaSessionDelegateAndroid,
+                                                DEFAULT_VOLUME_MULTIPLIER);
                     mIsDucking = false;
                 } else {
-                    nativeOnResume(mNativeMediaSession);
+                    nativeOnResume(mNativeMediaSessionDelegateAndroid);
                 }
                 break;
             case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
-                nativeOnSuspend(mNativeMediaSession, true);
+                nativeOnSuspend(mNativeMediaSessionDelegateAndroid, true);
                 break;
             case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
                 mIsDucking = true;
-                nativeRecordSessionDuck(mNativeMediaSession);
-                nativeOnSetVolumeMultiplier(mNativeMediaSession, DUCKING_VOLUME_MULTIPLIER);
+                nativeRecordSessionDuck(mNativeMediaSessionDelegateAndroid);
+                nativeOnSetVolumeMultiplier(mNativeMediaSessionDelegateAndroid,
+                                            DUCKING_VOLUME_MULTIPLIER);
                 break;
             case AudioManager.AUDIOFOCUS_LOSS:
                 abandonAudioFocus();
-                nativeOnSuspend(mNativeMediaSession, false);
+                nativeOnSuspend(mNativeMediaSessionDelegateAndroid, false);
                 break;
             default:
                 Log.w(TAG, "onAudioFocusChange called with unexpected value %d", focusChange);
@@ -95,9 +99,9 @@ public class MediaSession implements AudioManager.OnAudioFocusChangeListener {
         }
     }
 
-    private native void nativeOnSuspend(long nativeMediaSession, boolean temporary);
-    private native void nativeOnResume(long nativeMediaSession);
-    private native void nativeOnSetVolumeMultiplier(
-            long nativeMediaSession, double volumeMultiplier);
-    private native void nativeRecordSessionDuck(long nativeMediaSession);
+    private native void nativeOnSuspend(long nativeMediaSessionDelegateAndroid, boolean temporary);
+    private native void nativeOnResume(long nativeMediaSessionDelegateAndroid);
+    private native void nativeOnSetVolumeMultiplier(long nativeMediaSessionDelegateAndroid,
+                                                    double volumeMultiplier);
+    private native void nativeRecordSessionDuck(long nativeMediaSessionDelegateAndroid);
 }