Reland r187230: Implement the Stream registry in content

content/browser/streams/stream_read_observer.h

Index: content/browser/streams/stream_read_observer.h
diff --git a/content/browser/streams/stream_read_observer.h b/content/browser/streams/stream_read_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..a2b1bdc02a1018067139aa33043c3a8d441dce43
--- /dev/null
+++ b/content/browser/streams/stream_read_observer.h
@@ -0,0 +1,24 @@
+// Copyright (c) 2013 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 CONTENT_BROWSER_STREAMS_STREAM_READ_OBSERVER_H_
+#define CONTENT_BROWSER_STREAMS_STREAM_READ_OBSERVER_H_
+
+namespace content {
+
+class Stream;
+
+class StreamReadObserver {
+ public:
+  // Sent when there is data available to be read from the stream.
+  virtual void OnDataAvailable(Stream* stream) = 0;
+
+ protected:
+  virtual ~StreamReadObserver() {}
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_STREAMS_STREAM_READ_OBSERVER_H_
+