Worker: Introduce an observation mechanism for WorkerThread termination

third_party/WebKit/Source/modules/websockets/WorkerWebSocketChannel.h

Index: third_party/WebKit/Source/modules/websockets/WorkerWebSocketChannel.h
diff --git a/third_party/WebKit/Source/modules/websockets/WorkerWebSocketChannel.h b/third_party/WebKit/Source/modules/websockets/WorkerWebSocketChannel.h
index 2e9cf96b263a16a41766da9a44797008aa58374b..4244dd8609d4ef04276913e847d0f12118f64b3b 100644
--- a/third_party/WebKit/Source/modules/websockets/WorkerWebSocketChannel.h
+++ b/third_party/WebKit/Source/modules/websockets/WorkerWebSocketChannel.h
@@ -32,6 +32,7 @@
 #define WorkerWebSocketChannel_h
 
 #include "bindings/core/v8/SourceLocation.h"
+#include "core/workers/WorkerThreadLifecycleObserver.h"
 #include "modules/websockets/WebSocketChannel.h"
 #include "modules/websockets/WebSocketChannelClient.h"
 #include "platform/heap/Handle.h"
@@ -53,6 +54,7 @@ class ExecutionContextTask;
 class WebSocketChannelSyncHelper;
 class WorkerGlobalScope;
 class WorkerLoaderProxy;
+class WorkerThread;
 
 class WorkerWebSocketChannel final : public WebSocketChannel {
     WTF_MAKE_NONCOPYABLE(WorkerWebSocketChannel);
@@ -84,11 +86,11 @@ public:
 
     class Bridge;
     // Allocated in the worker thread, but used in the main thread.
-    class Peer final : public GarbageCollectedFinalized<Peer>, public WebSocketChannelClient {
+    class Peer final : public GarbageCollectedFinalized<Peer>, public WebSocketChannelClient, public WorkerThreadLifecycleObserver {
         USING_GARBAGE_COLLECTED_MIXIN(Peer);
         WTF_MAKE_NONCOPYABLE(Peer);
     public:
-        Peer(Bridge*, PassRefPtr<WorkerLoaderProxy>, WebSocketChannelSyncHelper*);
+        Peer(Bridge*, PassRefPtr<WorkerLoaderProxy>, WebSocketChannelSyncHelper*, WorkerThread*);
         ~Peer() override;
 
         // SourceLocation parameter may be shown when the connection fails.
@@ -113,6 +115,9 @@ public:
         void didClose(ClosingHandshakeCompletionStatus, unsigned short code, const String& reason) override;
         void didError() override;
 
+        // WorkerThreadLifecycleObserver function.
+        void contextDestroyed() override;
+
     private:
         Member<Bridge> m_bridge;
         RefPtr<WorkerLoaderProxy> m_loaderProxy;