Create a LinuxSandbox class.

content/common/sandbox_init_linux.cc

Index: content/common/sandbox_init_linux.cc
diff --git a/content/common/sandbox_init_linux.cc b/content/common/sandbox_init_linux.cc
index c7066c6267a97cf949cc4e44fc81bd494df57547..b9cafa2f2bcb702ce54b7bcf4adc97538cf0e965 100644
--- a/content/common/sandbox_init_linux.cc
+++ b/content/common/sandbox_init_linux.cc
@@ -32,6 +32,7 @@
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/time.h"
+#include "content/common/sandbox_linux.h"
 #include "content/public/common/content_switches.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
 
@@ -538,23 +539,6 @@ bool InitializeBpfSandbox_x86(const CommandLine& command_line,
   return true;
 }
 
-bool InitializeLegacySandbox_x86(const CommandLine& command_line,
-                                  const std::string& process_type) {
-#if defined(SECCOMP_SANDBOX)
-  // Start the old seccomp mode 1 (sandbox/linux/seccomp-legacy).
-  if (process_type == switches::kRendererProcess && SeccompSandboxEnabled()) {
-    // N.b. SupportsSeccompSandbox() returns a cached result, as we already
-    // called it earlier in the zygote. Thus, it is OK for us to not pass in
-    // a file descriptor for "/proc".
-    if (SupportsSeccompSandbox(-1)) {
-      StartSeccompSandbox();
-      return true;
-    }
-  }
-#endif
-  return false;
-}
-
 }  // anonymous namespace
 
 #endif  // defined(__i386__) || defined(__x86_64__)
@@ -571,7 +555,7 @@ void InitializeSandbox() {
 
   // First, try to enable seccomp-legacy.
   seccomp_legacy_started =
-      InitializeLegacySandbox_x86(command_line, process_type);
+      LinuxSandbox::GetInstance()->StartSeccompLegacy(process_type);
   if (seccomp_legacy_started)
     LogSandboxStarted("seccomp-legacy", process_type);