Add a command line option to turn off retry attempts to resolve host

chrome/common/chrome_switches.cc

 // Copyright (c) 2011 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/common/chrome_switches.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 
 namespace switches {
@@ skipping 583 matching lines @@
 //                               Will also force the port of the resulting
 //                               socket address to be 77.
 //    "MAP * baz, EXCLUDE www.google.com" --> Remaps everything to "baz",
 //                                            except for "www.google.com".
 //
 // These mappings apply to the endpoint host in a net::URLRequest (the TCP
 // connect and host resolver in a direct connection, and the CONNECT in an http
 // proxy connection, and the endpoint host in a SOCKS proxy connection).
 const char kHostRules[]                     = "host-rules";
 
-// The maximum number of concurrent host resolve requests (i.e. DNS) to allow.
+// The maximum number of concurrent host resolve requests (i.e. DNS) to allow
+// (not counting backup attempts which would also consume threads).
+// --host-resolver-retry-attempts must be set to zero for this to be exact.
 const char kHostResolverParallelism[]       = "host-resolver-parallelism";
 
+// The maximum number of retry attempts to resolve the host. Set this to zero
+// to disable host resolver retry attempts.
+const char kHostResolverRetryAttempts[]     = "host-resolver-retry-attempts";
+
 // These mappings only apply to the host resolver.
 const char kHostResolverRules[]             = "host-resolver-rules";
 
 // This switch will take the JSON-formatted HSTS specification and load it
 // as if it were a preloaded HSTS entry. It will take precedence over both
 // website-specified rules and built-in rules.
 // The JSON format is the same as that persisted in
 // <profile_dir>/Default/TransportSecurity
 const char kHstsHosts[]                     = "hsts-hosts";
 
@@ skipping 556 matching lines @@
 
 // -----------------------------------------------------------------------------
 // DO NOT ADD YOUR CRAP TO THE BOTTOM OF THIS FILE.
 //
 // You were going to just dump your switches here, weren't you? Instead,
 // please put them in alphabetical order above, or in order inside the
 // appropriate ifdef at the bottom. The order should match the header.
 // -----------------------------------------------------------------------------
 
 }  // namespace switches