Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/workers/WorkerMessagingProxy.cpp

Index: Source/core/workers/WorkerMessagingProxy.cpp
diff --git a/Source/core/workers/WorkerMessagingProxy.cpp b/Source/core/workers/WorkerMessagingProxy.cpp
index 425700aee6e39a6d218e3f5e5735e9339b91beee..fac92b62b996dd98c7a34fd6ec248706808096a2 100644
--- a/Source/core/workers/WorkerMessagingProxy.cpp
+++ b/Source/core/workers/WorkerMessagingProxy.cpp
@@ -166,10 +166,10 @@ void WorkerMessagingProxy::reportException(const String& errorMessage, int lineN
     // We don't bother checking the askedToTerminate() flag here, because exceptions should *always* be reported even if the thread is terminated.
     // This is intentionally different than the behavior in MessageWorkerTask, because terminated workers no longer deliver messages (section 4.6 of the WebWorker spec), but they do report exceptions.
 
-    RefPtr<ErrorEvent> event = ErrorEvent::create(errorMessage, sourceURL, lineNumber, columnNumber, 0);
+    RefPtr<ErrorEvent> event = ErrorEvent::create(errorMessage, sourceURL, lineNumber, columnNumber, nullptr);
     bool errorHandled = !m_workerObject->dispatchEvent(event);
     if (!errorHandled)
-        m_executionContext->reportException(event, 0, NotSharableCrossOrigin);
+        m_executionContext->reportException(event, nullptr, NotSharableCrossOrigin);
 }
 
 void WorkerMessagingProxy::reportConsoleMessage(MessageSource source, MessageLevel level, const String& message, int lineNumber, const String& sourceURL)
@@ -258,7 +258,7 @@ void WorkerMessagingProxy::workerGlobalScopeDestroyed()
     // This method is always the last to be performed, so the proxy is not needed for communication
     // in either side any more. However, the Worker object may still exist, and it assumes that the proxy exists, too.
     m_askedToTerminate = true;
-    m_workerThread = 0;
+    m_workerThread = nullptr;
 
     InspectorInstrumentation::workerGlobalScopeTerminated(m_executionContext.get(), this);