Support text track selection in video controls

Source/core/html/shadow/MediaControls.cpp

Index: Source/core/html/shadow/MediaControls.cpp
diff --git a/Source/core/html/shadow/MediaControls.cpp b/Source/core/html/shadow/MediaControls.cpp
index b0560f11dddbc156a7e77c71ccca1c75b39140a6..32fe7ffacfb00b8e4c135dc12eaf6d85f95671d3 100644
--- a/Source/core/html/shadow/MediaControls.cpp
+++ b/Source/core/html/shadow/MediaControls.cpp
@@ -59,6 +59,8 @@ MediaControls::MediaControls(HTMLMediaElement& mediaElement)
     , m_muteButton(nullptr)
     , m_volumeSlider(nullptr)
     , m_toggleClosedCaptionsButton(nullptr)
+    , m_textTrackListContainer(nullptr)
+    , m_textTrackList(nullptr)
     , m_fullScreenButton(nullptr)
     , m_castButton(nullptr)
     , m_overlayCastButton(nullptr)
@@ -95,6 +97,8 @@ PassRefPtrWillBeRawPtr<MediaControls> MediaControls::create(HTMLMediaElement& me
 //     +-MediaControlMuteButtonElement                 (-webkit-media-controls-mute-button)
 //     +-MediaControlVolumeSliderElement               (-webkit-media-controls-volume-slider)
 //     +-MediaControlToggleClosedCaptionsButtonElement (-webkit-media-controls-toggle-closed-captions-button)
+//     +-MediaControlTextTrackListContainerElement     (-webkit-media-controls-text-track-list-container)
+//     +-MediaControlTextTrackListElement              (-webkit-media-controls-text-track-list)
 //     +-MediaControlCastButtonElement                 (-internal-media-controls-cast-button)
 //     \-MediaControlFullscreenButtonElement           (-webkit-media-controls-fullscreen-button)
 void MediaControls::initializeControls()
@@ -148,6 +152,15 @@ void MediaControls::initializeControls()
     m_toggleClosedCaptionsButton = toggleClosedCaptionsButton.get();
     panel->appendChild(toggleClosedCaptionsButton.release());
 
+    RefPtrWillBeRawPtr<MediaControlTextTrackListContainerElement> textTrackListContainer =
+        MediaControlTextTrackListContainerElement::create(*this);
+    m_textTrackListContainer = textTrackListContainer.get();
+    RefPtrWillBeRawPtr<MediaControlTextTrackListElement> textTrackList =
+        MediaControlTextTrackListElement::create(*this);
+    m_textTrackList = textTrackList.get();
+    m_textTrackListContainer->appendChild(textTrackList.release());
+    panel->appendChild(textTrackListContainer.release());
+
     RefPtrWillBeRawPtr<MediaControlCastButtonElement> castButton = MediaControlCastButtonElement::create(*this, false);
     m_castButton = castButton.get();
     panel->appendChild(castButton.release());
@@ -354,6 +367,25 @@ void MediaControls::refreshClosedCaptionsButtonVisibility()
         m_toggleClosedCaptionsButton->hide();
 }
 
+void MediaControls::toggleTextTrackList()
+{
+    if (!mediaElement().hasClosedCaptions())
+        return;
+
+    bool isTrackListVisible = m_textTrackListContainer->isVisible();
+    // Media controls panel has overflow set to hidden. To display track list,
+    // overflow has to be set to visible.
+    m_panel->setInlineStyleProperty(CSSPropertyOverflow, CSSValueVisible, isTrackListVisible);
+    if (isTrackListVisible) {
+        m_textTrackListContainer->hide();
+        m_textTrackList->hide();
+    } else {
+        m_textTrackListContainer->show();
+        m_textTrackList->refreshTextTrackListMenu();
+        m_textTrackList->show();
+    }
+}
+
 static Element* elementFromCenter(Element& element)
 {
     RefPtrWillBeRawPtr<ClientRect> clientRect = element.getBoundingClientRect();