Adding new media controls to MediaNotification

content/browser/media/session/media_session_impl.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/media/session/media_session_impl.h"
 
 #include "content/browser/media/session/audio_focus_delegate.h"
 #include "content/browser/media/session/media_session_player_observer.h"
+#include "content/browser/media/session/media_session_service_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
+#include "content/public/browser/media_session.h"
+#include "content/public/browser/media_session_observer.h"
 #include "content/public/browser/web_contents.h"
-#include "content/public/browser/web_contents_delegate.h"
 #include "media/base/media_content_type.h"
 
 #if defined(OS_ANDROID)
 #include "content/browser/media/session/media_session_android.h"
 #include "jni/MediaSession_jni.h"
 #endif  // defined(OS_ANDROID)
 
 namespace content {
 
 namespace {
@@ skipping 67 matching lines @@
     observer.MediaSessionDestroyed();
   for (auto& observer : observers_)
     observer.StopObserving();
 }
 
 void MediaSessionImpl::WebContentsDestroyed() {
   // This should only work for tests. In production, all the players should have
   // already been removed before WebContents is destroyed.
 
   // TODO(zqzhang): refactor MediaSessionImpl, maybe move the interface used to
-  // talk
-  // with AudioFocusManager out to a seperate class. The AudioFocusManager unit
-  // tests then could mock the interface and abandon audio focus when
+  // talk with AudioFocusManager out to a seperate class. The AudioFocusManager
+  // unit tests then could mock the interface and abandon audio focus when
   // WebContents is destroyed. See https://crbug.com/651069
   players_.clear();
   pepper_players_.clear();
   AbandonSystemAudioFocusIfNeeded();
 }
 
+void MediaSessionImpl::SetMediaSessionService(
+    MediaSessionServiceImpl* service) {
+  service_ = service;

[whywhat, 2016/10/28 16:10:23]

nit: I assume this is supposed to be called only once? Otherwise should we do
something with the previous service?
If it's the former, maybe add a DCHECK that service_ is nullptr?

[Zhiqiang Zhang (Slow), 2016/11/01 15:24:15]

It could be set and unset.
My point is the service is created by RenderFrameHost, so if the RenderFrame
goes away, the service should be destroyed. However I'm not very sure if
WebContents/MediaSession will be destroyed at that moment. So let's be safe.

+}
+
 void MediaSessionImpl::AddObserver(MediaSessionObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void MediaSessionImpl::RemoveObserver(MediaSessionObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 void MediaSessionImpl::SetMetadata(
     const base::Optional<MediaMetadata>& metadata) {
@@ skipping 151 matching lines @@
 
   if (audio_focus_state_ != State::SUSPENDED)
     OnSuspendInternal(suspend_type, State::SUSPENDED);
 
   DCHECK(audio_focus_state_ == State::SUSPENDED);
   players_.clear();
 
   AbandonSystemAudioFocusIfNeeded();
 }
 
+void MediaSessionImpl::DidReceiveAction(
+    blink::mojom::MediaSessionAction action) {
+  if (service_)

[whywhat, 2016/10/28 16:10:23]

nit: Is it possible to have service_ nullptr? 

[Zhiqiang Zhang (Slow), 2016/11/01 15:24:15]

See my other reply.

+    service_->GetClient()->DidReceiveAction(action);
+}
+
+void MediaSessionImpl::OnMediaSessionEnabledAction(
+    blink::mojom::MediaSessionAction action) {
+  for (auto& observer : observers_)
+    observer.MediaSessionEnabledAction(action);
+}
+
+void MediaSessionImpl::OnMediaSessionDisabledAction(
+    blink::mojom::MediaSessionAction action) {
+  for (auto& observer : observers_)
+    observer.MediaSessionDisabledAction(action);
+}
+
 void MediaSessionImpl::StartDucking() {
   if (is_ducking_)
     return;
   is_ducking_ = true;
   UpdateVolumeMultiplier();
 }
 
 void MediaSessionImpl::StopDucking() {
   if (!is_ducking_)
     return;
@@ skipping 125 matching lines @@
     it.observer->OnSetVolumeMultiplier(it.player_id, GetVolumeMultiplier());
 
   UpdateWebContents();
 }
 
 MediaSessionImpl::MediaSessionImpl(WebContents* web_contents)
     : WebContentsObserver(web_contents),
       audio_focus_state_(State::INACTIVE),
       audio_focus_type_(
           AudioFocusManager::AudioFocusType::GainTransientMayDuck),
-      is_ducking_(false) {
+      is_ducking_(false),
+      service_(nullptr) {
 #if defined(OS_ANDROID)
   session_android_.reset(new MediaSessionAndroid(this));
 #endif  // defined(OS_ANDROID)
 }
 
 void MediaSessionImpl::Initialize() {
   delegate_ = AudioFocusDelegate::Create(this);
 }
 
 bool MediaSessionImpl::RequestSystemAudioFocus(
@@ skipping 50 matching lines @@
   DCHECK(success);
 
   pepper_players_.insert(PlayerIdentifier(observer, player_id));
 
   observer->OnSetVolumeMultiplier(player_id, GetVolumeMultiplier());
 
   return true;
 }
 
 }  // namespace content