Allow the seccomp sandbox to be enabled, even if the suid sandbox has...

chrome/renderer/renderer_main_platform_delegate_linux.cc

Index: chrome/renderer/renderer_main_platform_delegate_linux.cc
===================================================================
--- chrome/renderer/renderer_main_platform_delegate_linux.cc	(revision 31339)
+++ chrome/renderer/renderer_main_platform_delegate_linux.cc	(working copy)
@@ -37,9 +37,12 @@
   // The seccomp sandbox is started in the renderer.
   // http://code.google.com/p/seccompsandbox/
 #if defined(ARCH_CPU_X86_FAMILY) && !defined(CHROMIUM_SELINUX)
+  // 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 (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableSeccompSandbox) &&
-      SupportsSeccompSandbox()) {
+      SupportsSeccompSandbox(-1)) {
     StartSeccompSandbox();
   }
 #endif