Cleanup: Remove unneeded forward declarations from remoting.

remoting/protocol/jingle_stream_connector.h

Index: remoting/protocol/jingle_stream_connector.h
===================================================================
--- remoting/protocol/jingle_stream_connector.h	(revision 109590)
+++ remoting/protocol/jingle_stream_connector.h	(working copy)
@@ -5,6 +5,8 @@
 #ifndef REMOTING_PROTOCOL_JINGLE_STREAM_CONNECTOR_H_
 #define REMOTING_PROTOCOL_JINGLE_STREAM_CONNECTOR_H_
 
+#include <string>
+
 #include "base/memory/scoped_ptr.h"
 #include "net/base/completion_callback.h"
 #include "remoting/protocol/channel_authenticator.h"
@@ -15,10 +17,6 @@
 class TransportChannel;
 }  // namespace cricket
 
-namespace jingle_glue {
-class TransportChannelSocketAdapter;
-}  // namespace jingle_glue
-
 namespace net {
 class CertVerifier;
 class StreamSocket;