Don't remove StackTrace::OutputToStream() for FNL.

base/debug/stack_trace_posix.cc

 // 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.
 
 #include "base/debug/stack_trace.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
@@ skipping 741 matching lines @@
 void StackTrace::Print() const {
   // NOTE: This code MUST be async-signal safe (it's used by in-process
   // stack dumping signal handler). NO malloc or stdio is allowed here.
 
 #if !defined(__UCLIBC__) && !defined(FNL_MUSL)
   PrintBacktraceOutputHandler handler;
   ProcessBacktrace(trace_, count_, &handler);
 #endif
 }
 
-#if !defined(__UCLIBC__) && !defined(FNL_MUSL)
 void StackTrace::OutputToStream(std::ostream* os) const {
+#if defined(__UCLIBC__) || defined(FNL_MUSL)
+  (*os) << "(stack trace not supported)\n";
+#else
   StreamBacktraceOutputHandler handler(os);
   ProcessBacktrace(trace_, count_, &handler);
+#endif
 }
-#endif
 
 namespace internal {
 
 // NOTE: code from sandbox/linux/seccomp-bpf/demo.cc.
 char *itoa_r(intptr_t i, char *buf, size_t sz, int base, size_t padding) {
   // Make sure we can write at least one NUL byte.
   size_t n = 1;
   if (n > sz)
     return NULL;
 
@@ skipping 48 matching lines @@
     *ptr = *start;
     *start++ = ch;
   }
   return buf;
 }
 
 }  // namespace internal
 
 }  // namespace debug
 }  // namespace base