headless: Make it possible to override the DevTools server address

headless/app/headless_shell.cc

Index: headless/app/headless_shell.cc
diff --git a/headless/app/headless_shell.cc b/headless/app/headless_shell.cc
index e1348e328ed10634668affd59a479af1b29429ed..525ff12e1cf777f76f57b9410354919d2e0e619b 100644
--- a/headless/app/headless_shell.cc
+++ b/headless/app/headless_shell.cc
@@ -101,14 +101,18 @@ int main(int argc, const char** argv) {
   // Enable devtools if requested.
   base::CommandLine command_line(argc, argv);
   if (command_line.HasSwitch(switches::kRemoteDebuggingPort)) {
+    std::string address = kDevToolsHttpServerAddress;
+    if (command_line.HasSwitch(headless::switches::kRemoteDebuggingAddress)) {
+      address = command_line.GetSwitchValueASCII(
+          headless::switches::kRemoteDebuggingAddress);

[Mike West, 2016/04/26 08:04:37]

It seems reasonable to do some sanity checking here; maybe look at using
`net::ParseURLHostnameToAddress` to verify that the string you're given is
actually an IP address? Otherwise you'll potentially be in a bad state after the
call to assign the IP address to devtools below (the DCHECK wouldn't crash you
in non-debug mode).

[Sami, 2016/04/26 10:07:52]

Good point. I've now made this use net::ParseURLHostnameToAddress and to bail
out if that doesn't like the input (plus the same for port parsing).

+    }
     int parsed_port;
     std::string port_str =
         command_line.GetSwitchValueASCII(switches::kRemoteDebuggingPort);
     if (base::StringToInt(port_str, &parsed_port) &&
         base::IsValueInRangeForNumericType<uint16_t>(parsed_port)) {
       net::IPAddress devtools_address;
-      bool result =
-          devtools_address.AssignFromIPLiteral(kDevToolsHttpServerAddress);
+      bool result = devtools_address.AssignFromIPLiteral(address);
       DCHECK(result);
       builder.EnableDevToolsServer(net::IPEndPoint(
           devtools_address, base::checked_cast<uint16_t>(parsed_port)));