[Fetch API] Add streams predicates to BodyStreamBuffer

third_party/WebKit/Source/modules/fetch/BodyStreamBuffer.h

 // Copyright 2014 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.
 
 #ifndef BodyStreamBuffer_h
 #define BodyStreamBuffer_h
 
 #include "core/dom/DOMException.h"
 #include "core/streams/ReadableByteStream.h"
 #include "core/streams/ReadableByteStreamReader.h"
@@ skipping 37 matching lines @@
     bool hasPendingActivity() const;
     void stop();
 
     // UnderlyingSource
     void pullSource() override;
     ScriptPromise cancelSource(ScriptState*, ScriptValue reason) override;
 
     // WebDataConsumerHandle::Client
     void didGetReadable() override;
 
+    bool isStreamReadable() const;
+    bool isStreamClosed() const;
+    bool isStreamErrored() const;
+    bool isStreamLocked() const;
+    bool isStreamDisturbed() const;
+
     DEFINE_INLINE_TRACE()
     {
         visitor->trace(m_stream);
         visitor->trace(m_loader);
         UnderlyingSource::trace(visitor);
     }
 
 private:
     class LoaderClient;
     void close();
     void error();
     void processData();
     void endLoading();
     void stopLoading();
 
     OwnPtr<FetchDataConsumerHandle> m_handle;
     OwnPtr<FetchDataConsumerHandle::Reader> m_reader;
     Member<ReadableByteStream> m_stream;
     // We need this member to keep it alive while loading.
     Member<FetchDataLoader> m_loader;
     bool m_streamNeedsMore;
 };
 
 } // namespace blink
 
 #endif // BodyStreamBuffer_h