Adds support for the DHCP portion of the WPAD (proxy auto-discovery) protocol.

net/base/net_error_list.h

Index: net/base/net_error_list.h
diff --git a/net/base/net_error_list.h b/net/base/net_error_list.h
index 1147267d3e35ce8b6bdc5ef602bff3d0b61472cc..9cb233b361965823de59af73916e19127963ea35 100644
--- a/net/base/net_error_list.h
+++ b/net/base/net_error_list.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -444,6 +444,9 @@ NET_ERROR(RESPONSE_HEADERS_MULTIPLE_CONTENT_LENGTH, -346)
 // headers are missing, so we're expecting additional frames to complete them.
 NET_ERROR(INCOMPLETE_SPDY_HEADERS, -347)
 
+// No PAC URL configuration could be retrieved from DHCP.

[eroman, 2011/04/21 05:22:48]

nit: I suggest wording this a little more concretely.

"could not be retrieved from DHCP" is ambiguous as to whether this was a
failure, or whether we succeeded talking DHCP but there was no PAC URL being
advertised. I expect you are in fact lumping these two together, but could be
helpful for future readers to make the explicit.

[Jói, 2011/05/03 21:20:59]

Done.

+NET_ERROR(PAC_NOT_IN_DHCP, -348)
+
 // The cache does not have the requested entry.
 NET_ERROR(CACHE_MISS, -400)