Add methods for creating V8 extras-based ReadableStreams from C++

Source/core/streams/QueuingStrategyBase.cpp

Index: Source/core/streams/QueuingStrategyBase.cpp
diff --git a/Source/core/streams/QueuingStrategyBase.cpp b/Source/core/streams/QueuingStrategyBase.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..dd78319dd31f99821c048a7bf672fd3629ccb5de
--- /dev/null
+++ b/Source/core/streams/QueuingStrategyBase.cpp
@@ -0,0 +1,23 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/streams/QueuingStrategyBase.h"
+
+namespace blink {
+
+QueuingStrategyBase::QueuingStrategyBase(double highWaterMark) : m_highWaterMark(highWaterMark)
+{
+}
+
+double QueuingStrategyBase::highWaterMark()
+{
+    return m_highWaterMark;
+}
+
+DEFINE_TRACE(QueuingStrategyBase)
+{
+}
+
+} // namespace blink