Allow mremap() for the Seccomp-BPF sandbox in renderers.

content/common/sandbox_seccomp_bpf_linux.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 <asm/unistd.h>
 #include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/audit.h>
 #include <linux/filter.h>
@@ skipping 1230 matching lines @@
 
 ErrorCode RendererOrWorkerProcessPolicy_x86_64(int sysno) {
   switch (sysno) {
     case __NR_ioctl:  // TODO(jln) investigate legitimate use in the renderer
                       // and see if alternatives can be used.
     case __NR_fdatasync:
     case __NR_fsync:
 #if defined(__i386__) || defined(__x86_64__)
     case __NR_getrlimit:
 #endif
+    case __NR_mremap:   // See crbug.com/149834.
     case __NR_pread64:
     case __NR_pwrite64:
     case __NR_sched_get_priority_max:
     case __NR_sched_get_priority_min:
     case __NR_sched_getparam:
     case __NR_sched_getscheduler:
     case __NR_sched_setscheduler:
     case __NR_setpriority:
     case __NR_sysinfo:
     case __NR_times:
@@ skipping 182 matching lines @@
       // Process-specific policy.
       ShouldEnableSeccompBpf(process_type) &&
       SupportsSandbox()) {
     return StartBpfSandbox(command_line, process_type);
   }
 #endif
   return false;
 }
 
 }  // namespace content