Remove |using base::StringPiece| from net/spdy header files.

net/spdy/spdy_session.h

 // Copyright (c) 2012 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 NET_SPDY_SPDY_SESSION_H_
 #define NET_SPDY_SPDY_SESSION_H_
 
 #include <deque>
 #include <map>
 #include <set>
@@ skipping 815 matching lines @@
   void DeleteExpiredPushedStreams();
 
   // BufferedSpdyFramerVisitorInterface:
   void OnError(SpdyFramer::SpdyError error_code) override;
   void OnStreamError(SpdyStreamId stream_id,
                      const std::string& description) override;
   void OnPing(SpdyPingId unique_id, bool is_ack) override;
   void OnRstStream(SpdyStreamId stream_id, SpdyRstStreamStatus status) override;
   void OnGoAway(SpdyStreamId last_accepted_stream_id,
                 SpdyGoAwayStatus status,
-                StringPiece debug_data) override;
+                base::StringPiece debug_data) override;
   void OnDataFrameHeader(SpdyStreamId stream_id,
                          size_t length,
                          bool fin) override;
   void OnStreamFrameData(SpdyStreamId stream_id,
                          const char* data,
                          size_t len,
                          bool fin) override;
   void OnStreamPadding(SpdyStreamId stream_id, size_t len) override;
   SpdyHeadersHandlerInterface* OnHeaderFrameStart(
       SpdyStreamId stream_id) override;
@@ skipping 365 matching lines @@
   // Used for posting asynchronous IO tasks.  We use this even though
   // SpdySession is refcounted because we don't need to keep the SpdySession
   // alive if the last reference is within a RunnableMethod.  Just revoke the
   // method.
   base::WeakPtrFactory<SpdySession> weak_factory_;
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_SESSION_H_