Remove unused SpdyFrameType::EXTENSION.

PiperOrigin-RevId: 346983815
Change-Id: I03bc694ecb2774d0c0d3c132699f200a52944a1d

spdy/core/spdy_protocol.cc

diff --git a/spdy/core/spdy_protocol.cc b/spdy/core/spdy_protocol.cc
index cb4b9b8..2116025 100644
--- a/spdy/core/spdy_protocol.cc
+++ b/spdy/core/spdy_protocol.cc
@@ -125,8 +125,6 @@
       return "PRIORITY";
     case SpdyFrameType::ALTSVC:
       return "ALTSVC";
-    case SpdyFrameType::EXTENSION:
-      return "EXTENSION (unspecified)";
   }
   return "UNKNOWN_FRAME_TYPE";
 }

spdy/core/spdy_protocol.h

diff --git a/spdy/core/spdy_protocol.h b/spdy/core/spdy_protocol.h
index 44a00e3..175db51 100644
--- a/spdy/core/spdy_protocol.h
+++ b/spdy/core/spdy_protocol.h
@@ -100,12 +100,6 @@
   // ALTSVC is a public extension.
   ALTSVC = 0x0a,
   MAX_FRAME_TYPE = ALTSVC,
-  // The specific value of EXTENSION is meaningless; it is a placeholder used
-  // within SpdyFramer's state machine when handling unknown frames via an
-  // extension API.
-  // TODO(birenroy): Remove the fake EXTENSION value from the SpdyFrameType
-  // enum.
-  EXTENSION = 0xff
 };
 
 // Flags on data packets.