Introduce RequestWebSocketStream into HttpStreamFactory

net/websockets/websocket_stream.h

Index: net/websockets/websocket_stream.h
diff --git a/net/websockets/websocket_stream.h b/net/websockets/websocket_stream.h
index c69aa85a33c4f112a1dd20a0438c2f12c6230a0b..10631f4f566a5a0119cf178073b75199363f6c20 100644
--- a/net/websockets/websocket_stream.h
+++ b/net/websockets/websocket_stream.h
@@ -8,6 +8,7 @@
 #include "base/basictypes.h"
 #include "base/memory/scoped_vector.h"
 #include "net/base/completion_callback.h"
+#include "net/websockets/websocket_stream_base.h"
 
 namespace net {
 
@@ -30,7 +31,7 @@ struct WebSocketFrameChunk;
 // |callback| will be called when the operation is finished. Non-null |callback|
 // must be provided to these functions.
 
-class WebSocketStream {
+class WebSocketStream : public WebSocketStreamBase {
  public:
   WebSocketStream() {}
 
@@ -95,6 +96,9 @@ class WebSocketStream {
   // - RenewStreamForAuth for authentication (is this necessary?)
   // - GetSSLInfo, GetSSLCertRequsetInfo for SSL
 
+  // WebSocketStreamBase derived functions
+  virtual WebSocketStream* AsWebSocketStream() { return this; }
+
  private:
   DISALLOW_COPY_AND_ASSIGN(WebSocketStream);
 };