rebase: bump google.golang.org/grpc from 1.48.0 to 1.49.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.48.0 to 1.49.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.48.0...v1.49.0)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/google.golang.org/grpc/internal/transport/http2_client.go

@@ -78,6 +78,7 @@ type http2Client struct {
 	framer *framer
 	// controlBuf delivers all the control related tasks (e.g., window
 	// updates, reset streams, and various settings) to the controller.
+	// Do not access controlBuf with mu held.
 	controlBuf *controlBuffer
 	fc         *trInFlow
 	// The scheme used: https if TLS is on, http otherwise.
@@ -109,6 +110,7 @@ type http2Client struct {
 	waitingStreams        uint32
 	nextID                uint32
 
+	// Do not access controlBuf with mu held.
 	mu            sync.Mutex // guard the following variables
 	state         transportState
 	activeStreams map[uint32]*Stream
@@ -685,7 +687,6 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 				cleanup(err)
 				return err
 			}
-			t.activeStreams[id] = s
 			if channelz.IsOn() {
 				atomic.AddInt64(&t.czData.streamsStarted, 1)
 				atomic.StoreInt64(&t.czData.lastStreamCreatedTime, time.Now().UnixNano())
@@ -719,6 +720,13 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 		t.nextID += 2
 		s.id = h.streamID
 		s.fc = &inFlow{limit: uint32(t.initialWindowSize)}
+		t.mu.Lock()
+		if t.activeStreams == nil { // Can be niled from Close().
+			t.mu.Unlock()
+			return false // Don't create a stream if the transport is already closed.
+		}
+		t.activeStreams[s.id] = s
+		t.mu.Unlock()
 		if t.streamQuota > 0 && t.waitingStreams > 0 {
 			select {
 			case t.streamsQuotaAvailable <- struct{}{}:
@@ -744,13 +752,7 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 	}
 	for {
 		success, err := t.controlBuf.executeAndPut(func(it interface{}) bool {
-			if !checkForStreamQuota(it) {
-				return false
-			}
-			if !checkForHeaderListSize(it) {
-				return false
-			}
-			return true
+			return checkForHeaderListSize(it) && checkForStreamQuota(it)
 		}, hdr)
 		if err != nil {
 			// Connection closed.
@@ -1003,13 +1005,13 @@ func (t *http2Client) updateWindow(s *Stream, n uint32) {
 // for the transport and the stream based on the current bdp
 // estimation.
 func (t *http2Client) updateFlowControl(n uint32) {
-	t.mu.Lock()
-	for _, s := range t.activeStreams {
-		s.fc.newLimit(n)
-	}
-	t.mu.Unlock()
 	updateIWS := func(interface{}) bool {
 		t.initialWindowSize = int32(n)
+		t.mu.Lock()
+		for _, s := range t.activeStreams {
+			s.fc.newLimit(n)
+		}
+		t.mu.Unlock()
 		return true
 	}
 	t.controlBuf.executeAndPut(updateIWS, &outgoingWindowUpdate{streamID: 0, increment: t.fc.newLimit(n)})
@@ -1215,7 +1217,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 	default:
 		t.setGoAwayReason(f)
 		close(t.goAway)
-		t.controlBuf.put(&incomingGoAway{})
+		defer t.controlBuf.put(&incomingGoAway{}) // Defer as t.mu is currently held.
 		// Notify the clientconn about the GOAWAY before we set the state to
 		// draining, to allow the client to stop attempting to create streams
 		// before disallowing new streams on this connection.

vendor/google.golang.org/grpc/internal/transport/http2_server.go

@@ -945,15 +945,16 @@ func (t *http2Server) streamContextErr(s *Stream) error {
 
 // WriteHeader sends the header metadata md back to the client.
 func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
-	if s.updateHeaderSent() {
-		return ErrIllegalHeaderWrite
-	}
-
+	s.hdrMu.Lock()
+	defer s.hdrMu.Unlock()
 	if s.getState() == streamDone {
 		return t.streamContextErr(s)
 	}
 
-	s.hdrMu.Lock()
+	if s.updateHeaderSent() {
+		return ErrIllegalHeaderWrite
+	}
+
 	if md.Len() > 0 {
 		if s.header.Len() > 0 {
 			s.header = metadata.Join(s.header, md)
@@ -962,10 +963,8 @@ func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
 		}
 	}
 	if err := t.writeHeaderLocked(s); err != nil {
-		s.hdrMu.Unlock()
 		return status.Convert(err).Err()
 	}
-	s.hdrMu.Unlock()
 	return nil
 }
 
@@ -1013,17 +1012,19 @@ func (t *http2Server) writeHeaderLocked(s *Stream) error {
 // TODO(zhaoq): Now it indicates the end of entire stream. Revisit if early
 // OK is adopted.
 func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
+	s.hdrMu.Lock()
+	defer s.hdrMu.Unlock()
+
 	if s.getState() == streamDone {
 		return nil
 	}
-	s.hdrMu.Lock()
+
 	// TODO(mmukhi): Benchmark if the performance gets better if count the metadata and other header fields
 	// first and create a slice of that exact size.
 	headerFields := make([]hpack.HeaderField, 0, 2) // grpc-status and grpc-message will be there if none else.
 	if !s.updateHeaderSent() {                      // No headers have been sent.
 		if len(s.header) > 0 { // Send a separate header frame.
 			if err := t.writeHeaderLocked(s); err != nil {
-				s.hdrMu.Unlock()
 				return err
 			}
 		} else { // Send a trailer only response.
@@ -1052,7 +1053,7 @@ func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
 		endStream: true,
 		onWrite:   t.setResetPingStrikes,
 	}
-	s.hdrMu.Unlock()
+
 	success, err := t.controlBuf.execute(t.checkForHeaderListSize, trailingHeader)
 	if !success {
 		if err != nil {

vendor/google.golang.org/grpc/internal/transport/http_util.go

@@ -47,12 +47,6 @@ const (
 	http2MaxFrameLen = 16384 // 16KB frame
 	// http://http2.github.io/http2-spec/#SettingValues
 	http2InitHeaderTableSize = 4096
-	// baseContentType is the base content-type for gRPC.  This is a valid
-	// content-type on it's own, but can also include a content-subtype such as
-	// "proto" as a suffix after "+" or ";".  See
-	// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
-	// for more details.
-
 )
 
 var (