Remove SpdyPingControlFrame struct. Useful for SPDY 4 development.

net/spdy/spdy_framer.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_FRAMER_H_
 #define NET_SPDY_SPDY_FRAMER_H_
 
 #include <list>
 #include <map>
 #include <string>
@@ skipping 372 matching lines @@
   SpdyRstStreamControlFrame* CreateRstStream(SpdyStreamId stream_id,
                                              SpdyRstStreamStatus status) const;
   SpdySerializedFrame* SerializeRstStream(
       const SpdyRstStreamIR& rst_stream) const;
 
   // Creates an instance of SpdySettingsControlFrame. The SETTINGS frame is
   // used to communicate name/value pairs relevant to the communication channel.
   SpdySettingsControlFrame* CreateSettings(const SettingsMap& values) const;
   SpdySerializedFrame* SerializeSettings(const SpdySettingsIR& settings) const;
 
-  // Creates an instance of SpdyPingControlFrame. The unique_id is used to
+  // Creates and serializes a PING frame. The unique_id is used to
   // identify the ping request/response.
-  SpdyPingControlFrame* CreatePingFrame(uint32 unique_id) const;
+  SpdyFrame* CreatePingFrame(uint32 unique_id) const;
   SpdySerializedFrame* SerializePing(const SpdyPingIR& ping) const;
 
   // Creates and serializes a GOAWAY frame. The GOAWAY frame is used
   // prior to the shutting down of the TCP connection, and includes the
   // stream_id of the last stream the sender of the frame is willing to process
   // to completion.
   SpdyFrame* CreateGoAway(SpdyStreamId last_accepted_stream_id,
                           SpdyGoAwayStatus status) const;
   SpdySerializedFrame* SerializeGoAway(const SpdyGoAwayIR& goaway) const;
 
@@ skipping 258 matching lines @@
   // starts with HTTP.  If it does, we likely have an HTTP response.   This
   // isn't guaranteed though: we could have gotten a settings frame and then
   // corrupt data that just looks like HTTP, but deterministic checking requires
   // a lot more state.
   bool probable_http_response_;
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_FRAMER_H_