Create a LinuxSandbox class.

content/zygote/zygote_linux.cc

Index: content/zygote/zygote_linux.cc
diff --git a/content/zygote/zygote_linux.cc b/content/zygote/zygote_linux.cc
index 3fcd996194b3258d12c87112124fce9a1d9e5ff5..101ea7f00c32956c8ca438ee601fce70dbed6093 100644
--- a/content/zygote/zygote_linux.cc
+++ b/content/zygote/zygote_linux.cc
@@ -25,7 +25,7 @@
 #include "base/pickle.h"
 #include "base/posix/unix_domain_socket.h"
 #include "content/common/set_process_title.h"
-#include "content/common/sandbox_methods_linux.h"
+#include "content/common/sandbox_linux.h"
 #include "content/common/zygote_commands_linux.h"
 #include "content/public/common/content_descriptors.h"
 #include "content/public/common/zygote_fork_delegate_linux.h"
@@ -68,13 +68,9 @@ void SELinuxTransitionToTypeOrDie(const char* type) {
 }  // namespace
 
 Zygote::Zygote(int sandbox_flags,
-               ZygoteForkDelegate* helper,
-               int proc_fd_for_seccomp)
+               ZygoteForkDelegate* helper)
     : sandbox_flags_(sandbox_flags),
       helper_(helper),
-#if defined(SECCOMP_SANDBOX)
-      proc_fd_for_seccomp_(proc_fd_for_seccomp),
-#endif
       initial_uma_sample_(0),
       initial_uma_boundary_value_(0) {
   if (helper_) {
@@ -423,17 +419,9 @@ base::ProcessId Zygote::ReadArgsAndFork(const Pickle& pickle,
                                               uma_boundary_value);
   if (!child_pid) {
     // This is the child process.
-#if defined(SECCOMP_SANDBOX)
-    if (proc_fd_for_seccomp_ >= 0) {
-      if (process_type == switches::kRendererProcess &&
-          SeccompSandboxEnabled()) {
-        SeccompSandboxSetProcFd(proc_fd_for_seccomp_);
-      } else {
-        close(proc_fd_for_seccomp_);
-      }
-      proc_fd_for_seccomp_ = -1;
-    }
-#endif
+
+    // At this point, we finally know our process type.
+    LinuxSandbox::GetInstance()->PreinitializeSandboxFinish(process_type);
 
     close(kBrowserDescriptor);  // Our socket from the browser.
     if (UsingSUIDSandbox())