Revert of Remove references between RTCPeerConnection and RTCDataChannel.

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

Index: third_party/WebKit/Source/modules/mediastream/RTCDataChannel.cpp
diff --git a/third_party/WebKit/Source/modules/mediastream/RTCDataChannel.cpp b/third_party/WebKit/Source/modules/mediastream/RTCDataChannel.cpp
index ad474ad7430119692b6e050980a21891d8132821..1114ae62c28dee6d702e387969072b78c517d335 100644
--- a/third_party/WebKit/Source/modules/mediastream/RTCDataChannel.cpp
+++ b/third_party/WebKit/Source/modules/mediastream/RTCDataChannel.cpp
@@ -51,28 +51,30 @@
     exceptionState.throwDOMException(NotSupportedError, "Blob support not implemented yet");
 }
 
-RTCDataChannel* RTCDataChannel::create(ExecutionContext* context, PassOwnPtr<WebRTCDataChannelHandler> handler)
+RTCDataChannel* RTCDataChannel::create(ExecutionContext* context, RTCPeerConnection* connection, PassOwnPtr<WebRTCDataChannelHandler> handler)
 {
     ASSERT(handler);
-    return new RTCDataChannel(context, handler);
-}
-
-RTCDataChannel* RTCDataChannel::create(ExecutionContext* context, WebRTCPeerConnectionHandler* peerConnectionHandler, const String& label, const WebRTCDataChannelInit& init, ExceptionState& exceptionState)
+    return new RTCDataChannel(context, connection, handler);
+}
+
+RTCDataChannel* RTCDataChannel::create(ExecutionContext* context, RTCPeerConnection* connection, WebRTCPeerConnectionHandler* peerConnectionHandler, const String& label, const WebRTCDataChannelInit& init, ExceptionState& exceptionState)
 {
     OwnPtr<WebRTCDataChannelHandler> handler = adoptPtr(peerConnectionHandler->createDataChannel(label, init));
     if (!handler) {
         exceptionState.throwDOMException(NotSupportedError, "RTCDataChannel is not supported");
         return nullptr;
     }
-    return new RTCDataChannel(context, handler.release());
-}
-
-RTCDataChannel::RTCDataChannel(ExecutionContext* context, PassOwnPtr<WebRTCDataChannelHandler> handler)
+    return new RTCDataChannel(context, connection, handler.release());
+}
+
+RTCDataChannel::RTCDataChannel(ExecutionContext* context, RTCPeerConnection* connection, PassOwnPtr<WebRTCDataChannelHandler> handler)
     : m_executionContext(context)
     , m_handler(handler)
+    , m_stopped(false)
     , m_readyState(ReadyStateConnecting)
     , m_binaryType(BinaryTypeArrayBuffer)
     , m_scheduledEventTimer(this, &RTCDataChannel::scheduledEventTimerFired)
+    , m_connection(connection)
     , m_bufferedAmountLowThreshold(0U)
 {
     m_handler->setClient(this);
@@ -80,8 +82,11 @@
 
 RTCDataChannel::~RTCDataChannel()
 {
-    // Notify the client that the channel is gone.
-    m_handler->setClient(0);
+    // If the peer connection and the data channel die in the same
+    // GC cycle stop has not been called and we need to notify the
+    // client that the channel is gone.
+    if (!m_stopped)
+        m_handler->setClient(0);
 }
 
 RTCDataChannel::ReadyState RTCDataChannel::getHandlerState() const
@@ -230,12 +235,15 @@
 
 void RTCDataChannel::close()
 {
+    if (m_stopped)
+        return;
+
     m_handler->close();
 }
 
 void RTCDataChannel::didChangeReadyState(WebRTCDataChannelHandlerClient::ReadyState newState)
 {
-    if (m_readyState == ReadyStateClosed)
+    if (m_stopped || m_readyState == ReadyStateClosed)
         return;
 
     m_readyState = newState;
@@ -262,11 +270,17 @@
 
 void RTCDataChannel::didReceiveStringData(const WebString& text)
 {
+    if (m_stopped)
+        return;
+
     scheduleDispatchEvent(MessageEvent::create(text));
 }
 
 void RTCDataChannel::didReceiveRawData(const char* data, size_t dataLength)
 {
+    if (m_stopped)
+        return;
+
     if (m_binaryType == BinaryTypeBlob) {
         // FIXME: Implement.
         return;
@@ -281,6 +295,9 @@
 
 void RTCDataChannel::didDetectError()
 {
+    if (m_stopped)
+        return;
+
     scheduleDispatchEvent(Event::create(EventTypeNames::error));
 }
 
@@ -292,6 +309,14 @@
 ExecutionContext* RTCDataChannel::executionContext() const
 {
     return m_executionContext;
+}
+
+void RTCDataChannel::stop()
+{
+    m_stopped = true;
+    m_readyState = ReadyStateClosed;
+    m_handler->setClient(0);
+    m_executionContext = 0;
 }
 
 void RTCDataChannel::scheduleDispatchEvent(PassRefPtrWillBeRawPtr<Event> event)
@@ -304,6 +329,9 @@
 
 void RTCDataChannel::scheduledEventTimerFired(Timer<RTCDataChannel>*)
 {
+    if (m_stopped)
+        return;
+
     WillBeHeapVector<RefPtrWillBeMember<Event>> events;
     events.swap(m_scheduledEvents);
 
@@ -314,10 +342,19 @@
     events.clear();
 }
 
+void RTCDataChannel::clearWeakMembers(Visitor* visitor)
+{
+    if (Heap::isHeapObjectAlive(m_connection))
+        return;
+    stop();
+    m_connection = nullptr;
+}
+
 DEFINE_TRACE(RTCDataChannel)
 {
     visitor->trace(m_executionContext);
     visitor->trace(m_scheduledEvents);
+    visitor->template registerWeakMembers<RTCDataChannel, &RTCDataChannel::clearWeakMembers>(this);
     RefCountedGarbageCollectedEventTargetWithInlineData<RTCDataChannel>::trace(visitor);
 }