Decouple MediaSession/MediaSessionObserver from WebContents in Java[OBSOLETE, go to the combined CL]

content/public/android/java/src/org/chromium/content_public/browser/MediaSession.java

Index: content/public/android/java/src/org/chromium/content_public/browser/MediaSession.java
diff --git a/content/public/android/java/src/org/chromium/content_public/browser/MediaSession.java b/content/public/android/java/src/org/chromium/content_public/browser/MediaSession.java
new file mode 100644
index 0000000000000000000000000000000000000000..a8cab03082c2edaef3c94f998271e1969d235dad
--- /dev/null
+++ b/content/public/android/java/src/org/chromium/content_public/browser/MediaSession.java
@@ -0,0 +1,54 @@
+// 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.
+
+package org.chromium.content_public.browser;
+
+import org.chromium.base.ObserverList;
+import org.chromium.base.VisibleForTesting;
+import org.chromium.base.annotations.JNINamespace;
+
+/**
+ * The MediaSession Java wrapper to allow communicating with the native MediaSession object.
+ */
+@JNINamespace("content")
+public abstract class MediaSession {
+    /**
+     * @return The MediaSession associated with |contents|.
+     */
+    public static MediaSession fromWebContents(WebContents contents) {
+        return nativeGetMediaSessionFromWebContents(contents);
+    }
+
+    /**
+     * Add an observer to the MediaSession.
+     * @param observer The observer to add.
+     */
+    public abstract void addObserver(MediaSessionObserver observer);
+    /**

[mlamouri (slow - plz ping), 2016/10/28 10:24:50]

style: leave empty line after `addObserver`

[Zhiqiang Zhang (Slow), 2016/10/28 11:18:48]

Done.

+     * Add an observer to the MediaSession.
+     * @param observer The observer to remove.
+     */
+    public abstract void removeObserver(MediaSessionObserver observer);
+
+    /**
+     * @return The list of observers.
+     */
+    @VisibleForTesting
+    public abstract ObserverList.RewindableIterator<MediaSessionObserver> getObserversForTesting();
+
+    /**
+     * Resumes the media session.
+     */
+    public abstract void resume();
+    /**

[mlamouri (slow - plz ping), 2016/10/28 10:24:50]

style: leave empty line after `resume`

[Zhiqiang Zhang (Slow), 2016/10/28 11:18:48]

Done.

+     * Suspends the media session.
+     */
+    public abstract void suspend();
+    /**

[mlamouri (slow - plz ping), 2016/10/28 10:24:50]

style: leave empty line after `suspend` 

[Zhiqiang Zhang (Slow), 2016/10/28 11:18:48]

Done.

+     * Stops the media session.
+     */
+    public abstract void stop();
+
+    private static native MediaSession nativeGetMediaSessionFromWebContents(WebContents contents);
+}