Implement the MediaStreamTrackEvent constructor

third_party/WebKit/Source/modules/mediastream/MediaStreamTrackEvent.cpp

Index: third_party/WebKit/Source/modules/mediastream/MediaStreamTrackEvent.cpp
diff --git a/third_party/WebKit/Source/modules/mediastream/MediaStreamTrackEvent.cpp b/third_party/WebKit/Source/modules/mediastream/MediaStreamTrackEvent.cpp
index d60f74048a733e3f8b4c459b99c94918d36b3987..46c542eb5cda06277a078a6705d6619f1ba12c02 100644
--- a/third_party/WebKit/Source/modules/mediastream/MediaStreamTrackEvent.cpp
+++ b/third_party/WebKit/Source/modules/mediastream/MediaStreamTrackEvent.cpp
@@ -28,15 +28,28 @@
 
 namespace blink {
 
-MediaStreamTrackEvent* MediaStreamTrackEvent::create(const AtomicString& type, bool canBubble, bool cancelable, MediaStreamTrack* track)
+MediaStreamTrackEvent* MediaStreamTrackEvent::create(const AtomicString& type, MediaStreamTrack* track)
 {
-    return new MediaStreamTrackEvent(type, canBubble, cancelable, track);
+    return new MediaStreamTrackEvent(type, track);
 }
 
-MediaStreamTrackEvent::MediaStreamTrackEvent(const AtomicString& type, bool canBubble, bool cancelable, MediaStreamTrack* track)
-    : Event(type, canBubble, cancelable)
+MediaStreamTrackEvent::MediaStreamTrackEvent(const AtomicString& type, MediaStreamTrack* track)
+    : Event(type, false, false)
     , m_track(track)
 {
+    DCHECK(m_track);
+}
+
+MediaStreamTrackEvent* MediaStreamTrackEvent::create(const AtomicString& type, const MediaStreamTrackEventInit& initializer)
+{
+    return new MediaStreamTrackEvent(type, initializer);
+}
+
+MediaStreamTrackEvent::MediaStreamTrackEvent(const AtomicString& type, const MediaStreamTrackEventInit& initializer)
+    : Event(type, initializer)
+    , m_track(initializer.track())
+{
+    DCHECK(m_track);
 }
 
 MediaStreamTrackEvent::~MediaStreamTrackEvent()