Avoids the "re-encode HPACK as SPDY3" step.

net/spdy/spdy_session.h

Index: net/spdy/spdy_session.h
diff --git a/net/spdy/spdy_session.h b/net/spdy/spdy_session.h
index 328420b1880406b6210a5df48635b5fdb869fcd3..84e3bd999dc4b04e2dad52060b0f9164c2e19ff1 100644
--- a/net/spdy/spdy_session.h
+++ b/net/spdy/spdy_session.h
@@ -99,6 +99,7 @@ enum SpdyProtocolErrorDetails {
   SPDY_ERROR_INVALID_DATA_FRAME_FLAGS = 8,
   SPDY_ERROR_INVALID_CONTROL_FRAME_FLAGS = 9,
   SPDY_ERROR_UNEXPECTED_FRAME = 31,
+  SPDY_ERROR_INTERNAL_FRAMER_ERROR = 41,
   SPDY_ERROR_INVALID_CONTROL_FRAME_SIZE = 37,
   SPDY_ERROR_INVALID_STREAM_ID = 38,
   // SpdyRstStreamStatus mappings.
@@ -140,7 +141,7 @@ SpdyGoAwayStatus NET_EXPORT_PRIVATE MapNetErrorToGoAwayStatus(Error err);
 
 // If these compile asserts fail then SpdyProtocolErrorDetails needs
 // to be updated with new values, as do the mapping functions above.
-static_assert(15 == SpdyFramer::LAST_ERROR,
+static_assert(16 == SpdyFramer::LAST_ERROR,
               "SpdyProtocolErrorDetails / Spdy Errors mismatch");
 static_assert(17 == RST_STREAM_NUM_STATUS_CODES,
               "SpdyProtocolErrorDetails / RstStreamStatus mismatch");
@@ -885,9 +886,6 @@ class NET_EXPORT SpdySession : public BufferedSpdyFramerVisitorInterface,
                          size_t len) override;
   void OnStreamEnd(SpdyStreamId stream_id) override;
   void OnStreamPadding(SpdyStreamId stream_id, size_t len) override;
-  SpdyHeadersHandlerInterface* OnHeaderFrameStart(
-      SpdyStreamId stream_id) override;
-  void OnHeaderFrameEnd(SpdyStreamId stream_id, bool end_headers) override;
   void OnSettings(bool clear_persisted) override;
   void OnSetting(SpdySettingsIds id, uint8_t flags, uint32_t value) override;
   void OnWindowUpdate(SpdyStreamId stream_id, int delta_window_size) override;