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

This is Windows-only for now, and is disabled by default.  Start
Chrome with the flag --enable-dhcp-wpad to enable the feature.  See
discussion in comment on DhcpProxyScriptFetcherFactory for why this
needs to be done in a per-platform way rather than cross-platform.
The code is factored so that adding other platform implementations
will be straight forward.

Most of the implementation is stand-alone and extends the
ScriptProxyFetcher class hierarchy (and makes its interface slightly
more generic).  The integration point into existing code is in
InitProxyResolver, which previously handled fallback from DNS
auto-detect to custom PAC URL and now does fallback from DHCP to DNS
to custom PAC URL.

BUG=18575
TEST=net_unittests has good coverage for the new and changed code, but
manual tests on a network with a PAC URL configured in DHCP are also
needed.

Review URL: http://codereview.chromium.org/6831025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85646 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 15 insertions, 0 deletions

diff --git a/chrome/browser/net/connection_tester.cc b/chrome/browser/net/connection_tester.cc
index 84d45d9..3aa578e 100644
--- a/chrome/browser/net/connection_tester.cc
+++ b/chrome/browser/net/connection_tester.cc
@@ -26,6 +26,7 @@
 #include "net/http/http_auth_handler_factory.h"
 #include "net/http/http_cache.h"
 #include "net/http/http_network_session.h"
+#include "net/proxy/dhcp_proxy_script_fetcher_factory.h"
 #include "net/proxy/proxy_config_service_fixed.h"
 #include "net/proxy/proxy_script_fetcher_impl.h"
 #include "net/proxy/proxy_service.h"
@@ -182,10 +183,17 @@ class ExperimentURLRequestContext : public net::URLRequestContext {
       return net::ERR_NOT_IMPLEMENTED;
     }
 
+    net::DhcpProxyScriptFetcherFactory dhcp_factory;
+    if (CommandLine::ForCurrentProcess()->HasSwitch(
+        switches::kEnableDhcpWpad)) {
+      dhcp_factory.set_enabled(true);
+    }
+
     proxy_service->reset(net::ProxyService::CreateUsingV8ProxyResolver(
         config_service.release(),
         0u,
         new net::ProxyScriptFetcherImpl(proxy_request_context_),
+        dhcp_factory.Create(proxy_request_context_),
         host_resolver(),
         NULL,
         NULL));
diff --git a/chrome/browser/net/proxy_service_factory.cc b/chrome/browser/net/proxy_service_factory.cc
index ba1cb9a..cf97923 100644
--- a/chrome/browser/net/proxy_service_factory.cc
+++ b/chrome/browser/net/proxy_service_factory.cc
@@ -12,6 +12,7 @@
 #include "chrome/common/chrome_switches.h"
 #include "content/browser/browser_thread.h"
 #include "net/base/net_log.h"
+#include "net/proxy/dhcp_proxy_script_fetcher_factory.h"
 #include "net/proxy/proxy_config_service.h"
 #include "net/proxy/proxy_script_fetcher_impl.h"
 #include "net/proxy/proxy_service.h"
@@ -84,10 +85,16 @@ net::ProxyService* ProxyServiceFactory::CreateProxyService(
 
   net::ProxyService* proxy_service;
   if (use_v8) {
+    net::DhcpProxyScriptFetcherFactory dhcp_factory;
+    if (command_line.HasSwitch(switches::kEnableDhcpWpad)) {
+      dhcp_factory.set_enabled(true);
+    }
+
     proxy_service = net::ProxyService::CreateUsingV8ProxyResolver(
         proxy_config_service,
         num_pac_threads,
         new net::ProxyScriptFetcherImpl(context),
+        dhcp_factory.Create(context),
         context->host_resolver(),
         net_log,
         context->network_delegate());