4373801: Use rtc::scoped_refptr for webrtc::DataChannel objects

https://chromium-review.googlesource.com/c/chromium/src/+/4373801

patches/chromium/cherry-pick-b03973561862.patch

@@ -20,7 +20,7 @@ Cr-Commit-Position: refs/branch-heads/5845@{#300}
 Cr-Branched-From: 5a5dff63a4a4c63b9b18589819bebb2566c85443-refs/heads/main@{#1160321}
 
 diff --git a/third_party/blink/renderer/modules/peerconnection/rtc_data_channel.cc b/third_party/blink/renderer/modules/peerconnection/rtc_data_channel.cc
-index 78d28d60822f4ce206d869846235352224378076..f5fc9fc01397d46a1262d7747925f425c0677af2 100644
+index 78d28d60822f4ce206d869846235352224378076..91c20cbcc5042373964d57545177ff06074db564 100644
 --- a/third_party/blink/renderer/modules/peerconnection/rtc_data_channel.cc
 +++ b/third_party/blink/renderer/modules/peerconnection/rtc_data_channel.cc
 @@ -228,11 +228,12 @@ RTCDataChannel::Observer::Observer(
@@ -58,7 +58,7 @@ index 78d28d60822f4ce206d869846235352224378076..f5fc9fc01397d46a1262d7747925f425
  RTCDataChannel::RTCDataChannel(
      ExecutionContext* context,
 -    scoped_refptr<webrtc::DataChannelInterface> channel,
-+    rtc::scoped_refptr<webrtc::DataChannelInterface> data_channel,
++    scoped_refptr<webrtc::DataChannelInterface> data_channel,
      RTCPeerConnectionHandler* peer_connection_handler)
      : ExecutionContextLifecycleObserver(context),
        state_(webrtc::DataChannelInterface::kConnecting),
@@ -71,28 +71,12 @@ index 78d28d60822f4ce206d869846235352224378076..f5fc9fc01397d46a1262d7747925f425
        signaling_thread_(peer_connection_handler->signaling_thread()) {
    DCHECK(peer_connection_handler);
 
-@@ -328,19 +324,19 @@ RTCDataChannel::RTCDataChannel(
-   // channel state consistency.
-   peer_connection_handler->RunSynchronousOnceClosureOnSignalingThread(
-       CrossThreadBindOnce(
--          [](scoped_refptr<RTCDataChannel::Observer> observer,
-+          [](scoped_refptr<RTCDataChannel::Observer> observer_,
-              webrtc::DataChannelInterface::DataState current_state) {
-             scoped_refptr<webrtc::DataChannelInterface> channel =
-                 observer->channel();
--            channel->RegisterObserver(observer.get());
--            if (channel->state() != current_state) {
--              observer->OnStateChange();
-+            channel()->RegisterObserver(observer_.get());
-+            if (channel()->state() != state_) {
-+              observer_->OnStateChange();
-             }
-           },
+@@ -340,7 +336,7 @@ RTCDataChannel::RTCDataChannel(
            observer_, state_),
        "RegisterObserverAndGetStateUpdate");
 
 -  IncrementCounters(*channel.get());
-+  IncrementCounters(*channel().get());
++  IncrementCounters(*(observer_->channel()).get());
  }
 
  RTCDataChannel::~RTCDataChannel() = default;
@@ -108,35 +92,23 @@ index 78d28d60822f4ce206d869846235352224378076..f5fc9fc01397d46a1262d7747925f425
 
  void RTCDataChannel::ScheduleDispatchEvent(Event* event) {
 diff --git a/third_party/blink/renderer/modules/peerconnection/rtc_data_channel.h b/third_party/blink/renderer/modules/peerconnection/rtc_data_channel.h
-index 21bb39382ac0c6acbf984ffbda5f6a4e6c863432..e48c049cc2820b16a8496f08ef6e4b206d5a4cd0 100644
+index 21bb39382ac0c6acbf984ffbda5f6a4e6c863432..6959b8b1e3a0b586be68cb4a8d0389b7926b98fe 100644
 --- a/third_party/blink/renderer/modules/peerconnection/rtc_data_channel.h
 +++ b/third_party/blink/renderer/modules/peerconnection/rtc_data_channel.h
 @@ -152,7 +152,7 @@ class MODULES_EXPORT RTCDataChannel final
 
      const scoped_refptr<base::SingleThreadTaskRunner> main_thread_;
      WeakPersistent<RTCDataChannel> blink_channel_;
 -    scoped_refptr<webrtc::DataChannelInterface> webrtc_channel_;
-+    const rtc::scoped_refptr<webrtc::DataChannelInterface> webrtc_channel_;
++    const scoped_refptr<webrtc::DataChannelInterface> webrtc_channel_;
    };
 
    void OnStateChange(webrtc::DataChannelInterface::DataState state);
-@@ -191,11 +191,19 @@ class MODULES_EXPORT RTCDataChannel final
-   FrameScheduler::SchedulingAffectingFeatureHandle
-       feature_handle_for_scheduler_;
-
--  unsigned buffered_amount_low_threshold_;
--  unsigned buffered_amount_;
--  bool stopped_;
--  bool closed_from_owner_;
+@@ -195,7 +195,11 @@ class MODULES_EXPORT RTCDataChannel final
+   unsigned buffered_amount_;
+   bool stopped_;
+   bool closed_from_owner_;
 -  scoped_refptr<Observer> observer_;
-+  // Once an id has been assigned, we'll set this value and use it instead
-+  // of querying the channel (which requires thread hop). This is a cached
-+  // value to optimize a const getter, and therefore `mutable`.
-+  mutable absl::optional<uint16_t> id_;
-+  unsigned buffered_amount_low_threshold_ = 0u;
-+  unsigned buffered_amount_ = 0u;
-+  bool stopped_ = false;
-+  bool closed_from_owner_ = false;
 +  // Keep the `observer_` reference const to make it clear that we don't want
 +  // to free the underlying channel (or callback observer) until the
 +  // `RTCDataChannel` instance goes away. This allows properties to be queried