Remove code to block sync XHRs during microtask executions

third_party/WebKit/Source/core/xmlhttprequest/XMLHttpRequest.cpp

 /*
  *  Copyright (C) 2004, 2006, 2008 Apple Inc. All rights reserved.
  *  Copyright (C) 2005-2007 Alexey Proskuryakov <ap@webkit.org>
  *  Copyright (C) 2007, 2008 Julien Chaffraix <jchaffraix@webkit.org>
  *  Copyright (C) 2008, 2011 Google Inc. All rights reserved.
  *  Copyright (C) 2012 Intel Corporation
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
@@ skipping 614 matching lines @@
 {
     if (!getExecutionContext())
         return false;
 
     if (m_state != kOpened || m_loader) {
         exceptionState.throwDOMException(InvalidStateError, "The object's state must be OPENED.");
         return false;
     }
 
     if (!m_async && exceptionState.isolate() && v8::MicrotasksScope::IsRunningMicrotasks(exceptionState.isolate())) {
-        Deprecation::countDeprecation(getExecutionContext(), UseCounter::During_Microtask_SyncXHR);
-        if (RuntimeEnabledFeatures::disableBlockingMethodsDuringMicrotasksEnabled()) {
-            exceptionState.throwDOMException(InvalidAccessError, "Cannot send() synchronous requests during microtask execution.");
-            return false;
-        }
+        UseCounter::count(getExecutionContext(), UseCounter::During_Microtask_SyncXHR);
     }
 
 
     m_error = false;
     return true;
 }
 
 void XMLHttpRequest::send(const ArrayBufferOrArrayBufferViewOrBlobOrDocumentOrStringOrFormData& body, ExceptionState& exceptionState)
 {
     InspectorInstrumentation::willSendXMLHttpOrFetchNetworkRequest(getExecutionContext(), url());
@@ skipping 1070 matching lines @@
 
 DEFINE_TRACE_WRAPPERS(XMLHttpRequest)
 {
     visitor->traceWrappers(m_responseBlob);
     visitor->traceWrappers(m_responseLegacyStream);
     visitor->traceWrappers(m_responseDocument);
     visitor->traceWrappers(m_responseArrayBuffer);
 }
 
 } // namespace blink