Fix "unused variable" warnings.

content/common/sandbox_linux/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 "content/common/sandbox_linux/sandbox_seccomp_bpf_linux.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
@@ skipping 146 matching lines @@
     syscall_ret = socket(AF_NETLINK, SOCK_DGRAM, 0);
     CHECK_EQ(-1, syscall_ret);
     CHECK_EQ(EPERM, errno);
 #endif  // !defined(NDEBUG)
   }
 }
 
 std::unique_ptr<SandboxBPFBasePolicy> GetGpuProcessSandbox() {
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
-  bool allow_sysv_shm = false;
-  if (command_line.HasSwitch(switches::kGpuSandboxAllowSysVShm)) {
-    DCHECK(IsArchitectureArm());

[Peter Kasting, 2016/05/19 05:32:37]

Technically this DCHECK is incorrect; it's perfectly possible for someone to
pass this command-line flag while on the wrong architecture.  It won't do
anything in that case anyway, so there's no real reason to bother DCHECKing.

-    allow_sysv_shm = true;
-  }
-
   if (IsChromeOS() && IsArchitectureArm()) {
+    bool allow_sysv_shm =
+        command_line.HasSwitch(switches::kGpuSandboxAllowSysVShm);
     return std::unique_ptr<SandboxBPFBasePolicy>(
         new CrosArmGpuProcessPolicy(allow_sysv_shm));
   } else {
     bool allow_mincore = command_line.HasSwitch(switches::kUseGL) &&
                          command_line.GetSwitchValueASCII(switches::kUseGL) ==
                              gfx::kGLImplementationEGLName;
     return std::unique_ptr<SandboxBPFBasePolicy>(
         new GpuProcessPolicy(allow_mincore));
   }
 }
@@ skipping 119 matching lines @@
 SandboxSeccompBPF::GetBaselinePolicy() {
 #if defined(USE_SECCOMP_BPF)
   return std::unique_ptr<sandbox::bpf_dsl::Policy>(new BaselinePolicy);
 #else
   return std::unique_ptr<sandbox::bpf_dsl::Policy>();
 #endif  // defined(USE_SECCOMP_BPF)
 }
 #endif  // !defined(OS_NACL_NONSFI)
 
 }  // namespace content