Adding new media controls to MediaNotification

content/browser/media/session/media_session_impl.cc

Index: content/browser/media/session/media_session_impl.cc
diff --git a/content/browser/media/session/media_session_impl.cc b/content/browser/media/session/media_session_impl.cc
index c19b212baa26ba5cc787e14f988fe72a4be78b3b..76f0695e25875bb6bc4d726850fd6e75ef0b416f 100644
--- a/content/browser/media/session/media_session_impl.cc
+++ b/content/browser/media/session/media_session_impl.cc
@@ -6,9 +6,11 @@
 
 #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)
@@ -96,15 +98,19 @@ void MediaSessionImpl::WebContentsDestroyed() {
   // 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);
 }
@@ -276,6 +282,24 @@ void MediaSessionImpl::Stop(SuspendType suspend_type) {
   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;
@@ -421,7 +445,8 @@ MediaSessionImpl::MediaSessionImpl(WebContents* 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)