Remove unused HttpFrameType::PRIORITY_UPDATE.

PiperOrigin-RevId: 379749377
diff --git a/quic/core/http/http_decoder.cc b/quic/core/http/http_decoder.cc
index 5fd6b65..de0ae53 100644
--- a/quic/core/http/http_decoder.cc
+++ b/quic/core/http/http_decoder.cc
@@ -803,9 +803,6 @@
     case static_cast<uint64_t>(HttpFrameType::MAX_PUSH_ID):
       // TODO(b/171463363): Remove.
       return sizeof(PushId);
-    case static_cast<uint64_t>(HttpFrameType::PRIORITY_UPDATE):
-      // This limit is arbitrary.
-      return 1024 * 1024;
     case static_cast<uint64_t>(HttpFrameType::PRIORITY_UPDATE_REQUEST_STREAM):
       // This limit is arbitrary.
       return 1024 * 1024;
diff --git a/quic/core/http/http_frames.h b/quic/core/http/http_frames.h
index b14ebe5..286e8f7 100644
--- a/quic/core/http/http_frames.h
+++ b/quic/core/http/http_frames.h
@@ -28,12 +28,9 @@
   PUSH_PROMISE = 0x5,
   GOAWAY = 0x7,
   MAX_PUSH_ID = 0xD,
-  // https://tools.ietf.org/html/draft-ietf-httpbis-priority-01
-  // TODO(b/147306124): Remove.
-  PRIORITY_UPDATE = 0XF,
   // https://tools.ietf.org/html/draft-davidben-http-client-hint-reliability-02
   ACCEPT_CH = 0x89,
-  // https://tools.ietf.org/html/draft-ietf-httpbis-priority-02
+  // https://tools.ietf.org/html/draft-ietf-httpbis-priority-03
   PRIORITY_UPDATE_REQUEST_STREAM = 0xF0700,
   // https://www.ietf.org/archive/id/draft-ietf-webtrans-http3-00.html
   WEBTRANSPORT_STREAM = 0x41,
@@ -144,10 +141,9 @@
 // https://httpwg.org/http-extensions/draft-ietf-httpbis-priority.html
 //
 // The PRIORITY_UPDATE frame specifies the sender-advised priority of a stream.
-// https://tools.ietf.org/html/draft-ietf-httpbis-priority-01 uses frame type
-// 0x0f, both for request streams and push streams.
-// https://tools.ietf.org/html/draft-ietf-httpbis-priority-02 uses frame types
-// 0xf0700 for request streams and 0xf0701 for push streams (not implemented).
+// Frame type 0xf0700 (called PRIORITY_UPDATE_REQUEST_STREAM in the
+// implementation) is used for for request streams.
+// Frame type 0xf0701 is used for push streams and is not implemented.
 
 // Length of a priority frame's first byte.
 const QuicByteCount kPriorityFirstByteLength = 1;
diff --git a/quic/core/http/quic_receive_control_stream.cc b/quic/core/http/quic_receive_control_stream.cc
index 39d8b42..e00ddc6 100644
--- a/quic/core/http/quic_receive_control_stream.cc
+++ b/quic/core/http/quic_receive_control_stream.cc
@@ -170,7 +170,7 @@
 
 bool QuicReceiveControlStream::OnPriorityUpdateFrameStart(
     QuicByteCount /*header_length*/) {
-  return ValidateFrameType(HttpFrameType::PRIORITY_UPDATE);
+  return ValidateFrameType(HttpFrameType::PRIORITY_UPDATE_REQUEST_STREAM);
 }
 
 bool QuicReceiveControlStream::OnPriorityUpdateFrame(
diff --git a/quic/core/http/quic_receive_control_stream_test.cc b/quic/core/http/quic_receive_control_stream_test.cc
index ec74af5..169af21 100644
--- a/quic/core/http/quic_receive_control_stream_test.cc
+++ b/quic/core/http/quic_receive_control_stream_test.cc
@@ -260,7 +260,7 @@
   EXPECT_CALL(*connection_,
               CloseConnection(QUIC_HTTP_MISSING_SETTINGS_FRAME,
                               "First frame received on control stream is type "
-                              "15, but it must be SETTINGS.",
+                              "984832, but it must be SETTINGS.",
                               _))
       .WillOnce(
           Invoke(connection_, &MockQuicConnection::ReallyCloseConnection));