Worker: Early return if termination is requested while worker thread is starting

third_party/WebKit/Source/core/workers/WorkerThread.cpp

Index: third_party/WebKit/Source/core/workers/WorkerThread.cpp
diff --git a/third_party/WebKit/Source/core/workers/WorkerThread.cpp b/third_party/WebKit/Source/core/workers/WorkerThread.cpp
index f78949695aba6d80d8f58a301e0a4bb9ed1779e9..07896af90af00783e7e8521ddab9811cb381677c 100644
--- a/third_party/WebKit/Source/core/workers/WorkerThread.cpp
+++ b/third_party/WebKit/Source/core/workers/WorkerThread.cpp
@@ -487,9 +487,16 @@ void WorkerThread::initializeOnWorkerThread(std::unique_ptr<WorkerThreadStartupD
         }
     }
 
-    if (startMode == PauseWorkerGlobalScopeOnStart)
+    if (startMode == PauseWorkerGlobalScopeOnStart) {
         startRunningDebuggerTasksOnPauseOnWorkerThread();
 
+        // WorkerThread may be ready to shut down at this point if termination
+        // is requested while the debugger task is running. Shutdown sequence
+        // will start soon.
+        if (m_readyToShutdown)
+            return;
+    }
+
     if (m_workerGlobalScope->scriptController()->isContextInitialized()) {
         m_workerReportingProxy.didInitializeWorkerContext();
         v8::HandleScope handleScope(isolate());