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

chrome/browser/zygote_host_linux.cc

 // Copyright (c) 2009 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 "chrome/browser/zygote_host_linux.h"
 
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
@@ skipping 46 matching lines @@
   CHECK(socketpair(PF_UNIX, SOCK_SEQPACKET, 0, fds) == 0);
   base::file_handle_mapping_vector fds_to_map;
   fds_to_map.push_back(std::make_pair(fds[1], 3));
 
   const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
   if (browser_command_line.HasSwitch(switches::kZygoteCmdPrefix)) {
     const std::wstring prefix =
         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;
 
   // In Chromium branded builds, developers can set an environment variable to
   // use the development sandbox. See
   // http://code.google.com/p/chromium/wiki/LinuxSUIDSandboxDevelopment
   if (stat("/proc/self/exe", &st) == 0 &&
       st.st_uid == getuid()) {
     sandbox_binary = getenv("CHROME_DEVEL_SANDBOX");
@@ skipping 102 matching lines @@
       !read_pickle.ReadBool(&iter, &tmp_child_exited)) {
     LOG(WARNING) << "Error parsing DidProcessCrash response from zygote.";
     return false;
   }
 
   if (child_exited)
     *child_exited = tmp_child_exited;
 
   return did_crash;
 }