Link MediaSessionTabHelper with native MediaSession [CL is going to be split]

content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsObserverProxy.java

 // 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.
 
 package org.chromium.content.browser.webcontents;
 
 import org.chromium.base.ObserverList;
 import org.chromium.base.ObserverList.RewindableIterator;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.content_public.browser.WebContentsObserver;
-import org.chromium.content_public.common.MediaMetadata;
 
 /**
  * Serves as a compound observer proxy for dispatching WebContentsObserver callbacks,
  * avoiding redundant JNI-related work when there are multiple Java-based observers.
  */
 @JNINamespace("content")
 class WebContentsObserverProxy extends WebContentsObserver {
     private long mNativeWebContentsObserverProxy;
     private final ObserverList<WebContentsObserver> mObservers;
     private final RewindableIterator<WebContentsObserver> mObserversIterator;
@@ skipping 200 matching lines @@
     @Override
     @CalledByNative
     public void didStartNavigationToPendingEntry(String url) {
         for (mObserversIterator.rewind(); mObserversIterator.hasNext();) {
             mObserversIterator.next().didStartNavigationToPendingEntry(url);
         }
     }
 
     @Override
     @CalledByNative
-    public void mediaSessionStateChanged(boolean isControllable, boolean isSuspended) {
-        for (mObserversIterator.rewind(); mObserversIterator.hasNext();) {
-            mObserversIterator.next().mediaSessionStateChanged(isControllable, isSuspended);
-        }
-    }
-
-    @Override
-    @CalledByNative
-    public void mediaSessionMetadataChanged(MediaMetadata metadata) {
-        for (mObserversIterator.rewind(); mObserversIterator.hasNext();) {
-            mObserversIterator.next().mediaSessionMetadataChanged(metadata);
-        }
-    }
-
-    @Override
-    @CalledByNative
     public void destroy() {
         // Super destruction semantics (removing the observer from the
         // Java-based WebContents) are quite different, so we explicitly avoid
         // calling it here.
         ThreadUtils.assertOnUiThread();
         for (mObserversIterator.rewind(); mObserversIterator.hasNext();) {
             mObserversIterator.next().destroy();
         }
         // All observer destroy() implementations should result in their removal
         // from the proxy.
         assert mObservers.isEmpty();
         mObservers.clear();
 
         if (mNativeWebContentsObserverProxy != 0) {
             nativeDestroy(mNativeWebContentsObserverProxy);
             mNativeWebContentsObserverProxy = 0;
         }
     }
 
     private native long nativeInit(WebContentsImpl webContents);
     private native void nativeDestroy(long nativeWebContentsObserverProxy);
 }