Bug 1623486 - part4 : update Picture-in-Picture mode status from media element. r=chunmin,padenot

Video element can start the Picture-in-Picture mode **BEFORE** or **AFTER** we start the listener for the media cotrol, so we have to ensure we always propagate this information to the chrome process via `ContentMediaAgent`.

Differential Revision: https://phabricator.services.mozilla.com/D67712

--HG--
extra : moz-landing-system : lando

dom/html/HTMLMediaElement.cpp

@@ -472,6 +472,17 @@ class HTMLMediaElement::MediaControlEventListener final
     }
   }
 
+  void SetPictureInPictureModeEnabled(bool aIsEnabled) {
+    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(IsStarted());
+    if (mIsPictureInPictureEnabled == aIsEnabled) {
+      return;
+    }
+    mIsPictureInPictureEnabled = aIsEnabled;
+    mControlAgent->NotifyPictureInPictureModeChanged(
+        this, mIsPictureInPictureEnabled);
+  }
+
   void OnKeyPressed(MediaControlKeysEvent aEvent) override {
     MOZ_ASSERT(NS_IsMainThread());
     MOZ_ASSERT(IsStarted());
@@ -528,6 +539,7 @@ class HTMLMediaElement::MediaControlEventListener final
   ControlledMediaState mState = ControlledMediaState::eStopped;
   WeakPtr<HTMLMediaElement> mElement;
   RefPtr<ContentMediaAgent> mControlAgent;
+  bool mIsPictureInPictureEnabled = false;
   bool mIsOwnerAudible = false;
 };
 
@@ -7736,6 +7748,11 @@ void HTMLMediaElement::StartListeningMediaControlEventIfNeeded() {
   // but the audible state update could happen before that. Therefore, we have
   // to manually update media's audible state as well.
   mMediaControlEventListener->UpdateMediaAudibleState(IsAudible());
+
+  // Picture-in-Picture mode can be enabled before we start the listener so we
+  // manually update the status here in case not to forgot to propagate that.
+  mMediaControlEventListener->SetPictureInPictureModeEnabled(
+      IsBeingUsedInPictureInPictureMode());
 }
 
 void HTMLMediaElement::StopListeningMediaControlEventIfNeeded() {
@@ -7795,6 +7812,19 @@ void HTMLMediaElement::ClearStopMediaControlTimerIfNeeded() {
   }
 }
 
+void HTMLMediaElement::UpdateMediaControlAfterPictureInPictureModeChanged() {
+  // Hasn't started to connect with media control, no need to update anything.
+  if (!mMediaControlEventListener || !mMediaControlEventListener->IsStarted()) {
+    return;
+  }
+  if (IsBeingUsedInPictureInPictureMode()) {
+    mMediaControlEventListener->SetPictureInPictureModeEnabled(true);
+  } else {
+    mMediaControlEventListener->SetPictureInPictureModeEnabled(false);
+    CreateStopMediaControlTimerIfNeeded();
+  }
+}
+
 bool HTMLMediaElement::IsBeingUsedInPictureInPictureMode() const {
   if (!IsVideo()) {
     return false;

dom/html/HTMLMediaElement.h

@@ -1346,6 +1346,10 @@ class HTMLMediaElement : public nsGenericHTMLElement,
   // key events.
   void ClearStopMediaControlTimerIfNeeded();
 
+  // This function is used to update the status of media control when the media
+  // changes its status of being used in the Picture-in-Picture mode.
+  void UpdateMediaControlAfterPictureInPictureModeChanged();
+
   // The current decoder. Load() has been called on this decoder.
   // At most one of mDecoder and mSrcStream can be non-null.
   RefPtr<MediaDecoder> mDecoder;

dom/html/HTMLVideoElement.cpp

@@ -552,6 +552,7 @@ void HTMLVideoElement::MaybeBeginCloningVisually() {
     if (container) {
       mDecoder->SetSecondaryVideoContainer(container);
     }
+    UpdateMediaControlAfterPictureInPictureModeChanged();
   } else if (mSrcStream) {
     VideoFrameContainer* container =
         mVisualCloneTarget->GetVideoFrameContainer();
@@ -561,6 +562,7 @@ void HTMLVideoElement::MaybeBeginCloningVisually() {
           this, container, mAbstractMainThread);
       mSelectedVideoStreamTrack->AddVideoOutput(mSecondaryVideoOutput);
     }
+    UpdateMediaControlAfterPictureInPictureModeChanged();
   }
 }
 
@@ -582,7 +584,7 @@ void HTMLVideoElement::EndCloningVisually() {
   Unused << mVisualCloneTarget->SetVisualCloneSource(nullptr);
   Unused << SetVisualCloneTarget(nullptr);
 
-  CreateStopMediaControlTimerIfNeeded();
+  UpdateMediaControlAfterPictureInPictureModeChanged();
 
   if (IsInComposedDoc() && !StaticPrefs::media_cloneElementVisually_testing()) {
     NotifyUAWidgetSetupOrChange();