linux: add command-line flag to allow debugging of sandboxed processes

chrome/browser/zygote_host_linux.cc

Index: chrome/browser/zygote_host_linux.cc
diff --git a/chrome/browser/zygote_host_linux.cc b/chrome/browser/zygote_host_linux.cc
index b0558349de8593065a108404b9d3ef1a843563cd..9f9e4aad3fe6f69628d0cc0eb3d6c7a2682596d2 100644
--- a/chrome/browser/zygote_host_linux.cc
+++ b/chrome/browser/zygote_host_linux.cc
@@ -64,6 +64,9 @@ ZygoteHost::ZygoteHost() {
         browser_command_line.GetSwitchValue(switches::kZygoteCmdPrefix);
     cmd_line.PrependWrapper(prefix);
   }
+  if (browser_command_line.HasSwitch(switches::kAllowSandboxDebugging)) {
+    cmd_line.AppendSwitch(switches::kAllowSandboxDebugging);
+  }
 
   const char* sandbox_binary = NULL;
   struct stat st;