Clone MediaStreamTrack's readyState property

MediaStreamTrack's clone should have the same state.
This CL ensures that MediaStreamTrack.clone().readyState
returns the same value as MediaStreamTrack.readyState.

Bug: 669212
Change-Id: I7547aff039ecdef5fb6d059957ea3566c798d86f
Reviewed-on: https://chromium-review.googlesource.com/996837
Commit-Queue: Chandan Padhi <c.padhi@samsung.com>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548699}

third_party/WebKit/LayoutTests/fast/mediastream/MediaStreamTrack-clone.html

@@ -32,6 +32,18 @@ test(t => {
                     "Tracks enabled status should not be linked.");
 }, "Clones of disabled MediaStreamTracks are still disabled.");
 
+test(t => {
+  track = createTrack();
+  assert_equals(track.readyState, "live");
+  cloned_track1 = track.clone();
+  assert_equals(cloned_track1.readyState, "live");
+  track.stop();
+  assert_equals(track.readyState, "ended");
+  cloned_track2 = track.clone();
+  assert_equals(cloned_track2.readyState, "ended");
+  assert_equals(cloned_track1.readyState, "live");
+}, "Cloned MediaStreamTracks have same states");
+
 promise_test(function() {
   return navigator.mediaDevices.getUserMedia({audio: { echoCancellation: true }})
     .then(function(s) {

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

@@ -140,10 +140,18 @@ MediaStreamTrack* MediaStreamTrack::Create(ExecutionContext* context,
 
 MediaStreamTrack::MediaStreamTrack(ExecutionContext* context,
                                    MediaStreamComponent* component)
+    : MediaStreamTrack(context,
+                       component,
+                       component->Source()->GetReadyState(),
+                       false /* stopped */) {}
+
+MediaStreamTrack::MediaStreamTrack(ExecutionContext* context,
+                                   MediaStreamComponent* component,
+                                   MediaStreamSource::ReadyState ready_state,
+                                   bool stopped)
     : ContextLifecycleObserver(context),
-      ready_state_(component->Source()->GetReadyState()),
-      is_iterating_registered_media_streams_(false),
-      stopped_(false),
+      ready_state_(ready_state),
+      stopped_(stopped),
       component_(component) {
   component_->Source()->AddObserver(this);
 
@@ -291,11 +299,10 @@ void MediaStreamTrack::stopTrack(ExecutionContext* execution_context) {
 }
 
 MediaStreamTrack* MediaStreamTrack::clone(ScriptState* script_state) {
-  // TODO(pbos): Make sure m_readyState and m_stopped carries over on cloned
-  // tracks.
   MediaStreamComponent* cloned_component = Component()->Clone();
-  MediaStreamTrack* cloned_track = MediaStreamTrack::Create(
-      ExecutionContext::From(script_state), cloned_component);
+  MediaStreamTrack* cloned_track =
+      new MediaStreamTrack(ExecutionContext::From(script_state),
+                           cloned_component, ready_state_, stopped_);
   MediaStreamCenter::Instance().DidCloneMediaStreamTrack(Component(),
                                                          cloned_component);
   return cloned_track;

third_party/WebKit/Source/modules/mediastream/MediaStreamTrack.h

@@ -113,6 +113,10 @@ class MODULES_EXPORT MediaStreamTrack
   friend class CanvasCaptureMediaStreamTrack;
 
   MediaStreamTrack(ExecutionContext*, MediaStreamComponent*);
+  MediaStreamTrack(ExecutionContext*,
+                   MediaStreamComponent*,
+                   MediaStreamSource::ReadyState,
+                   bool stopped);
 
   // MediaStreamSourceObserver
   void SourceChangedState() override;
@@ -123,7 +127,7 @@ class MODULES_EXPORT MediaStreamTrack
 
   MediaStreamSource::ReadyState ready_state_;
   HeapHashSet<Member<MediaStream>> registered_media_streams_;
-  bool is_iterating_registered_media_streams_;
+  bool is_iterating_registered_media_streams_ = false;
   bool stopped_;
   Member<MediaStreamComponent> component_;
   Member<ImageCapture> image_capture_;