Makes RenderFrameObserver/RenderViewObserver::OnDestruct pure virtual.

content/renderer/media/android/renderer_media_session_manager.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/renderer/media/android/renderer_media_session_manager.h"
 
 #include "base/logging.h"
 #include "content/common/media/media_session_messages_android.h"
 #include "content/public/common/media_metadata.h"
 #include "content/public/renderer/render_thread.h"
@@ skipping 15 matching lines @@
 bool RendererMediaSessionManager::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(RendererMediaSessionManager, msg)
     IPC_MESSAGE_HANDLER(MediaSessionMsg_DidActivate, OnDidActivate)
     IPC_MESSAGE_HANDLER(MediaSessionMsg_DidDeactivate, OnDidDeactivate)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
+void RendererMediaSessionManager::OnDestruct() {
+  delete this;
+}
+
 int RendererMediaSessionManager::RegisterMediaSession(
     WebMediaSessionAndroid* session) {
   sessions_[next_session_id_] = session;
   return next_session_id_++;
 }
 
 void RendererMediaSessionManager::UnregisterMediaSession(int session_id) {
   sessions_.erase(session_id);
 }
 
@@ skipping 42 matching lines @@
   pending_activation_requests_.Remove(request_id);
 }
 
 void RendererMediaSessionManager::OnDidDeactivate(int request_id) {
   DCHECK(pending_deactivation_requests_.Lookup(request_id)) << request_id;
   pending_deactivation_requests_.Lookup(request_id)->onSuccess();
   pending_deactivation_requests_.Remove(request_id);
 }
 
 }  // namespace content