Enable using system proxy resolver for android webview.

android_webview/browser/net/aw_url_request_context_getter.cc

 // Copyright (c) 2012 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 "android_webview/browser/net/aw_url_request_context_getter.h"
 
 #include <vector>
 
 #include "android_webview/browser/aw_browser_context.h"
 #include "android_webview/browser/aw_content_browser_client.h"
@@ skipping 182 matching lines @@
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(!url_request_context_);
 
   net::URLRequestContextBuilder builder;
   builder.set_user_agent(GetUserAgent());
   AwNetworkDelegate* aw_network_delegate = new AwNetworkDelegate();
   builder.set_network_delegate(aw_network_delegate);
 #if !defined(DISABLE_FTP_SUPPORT)
   builder.set_ftp_enabled(false);  // Android WebView does not support ftp yet.
 #endif
-  if (data_reduction_proxy_config_service_.get()) {
-    builder.set_proxy_config_service(
-        data_reduction_proxy_config_service_.release());
-  } else {
-    builder.set_proxy_config_service(
-        net::ProxyService::CreateSystemProxyConfigService(
-            GetNetworkTaskRunner(), NULL /* Ignored on Android */ ));
-  }
+  DCHECK(data_reduction_proxy_config_service_.get());
+  // Create proxy without a resolver since we rely on system proxy resolver.

[eroman, 2014/11/21 01:55:15]

I don't follow this comment. If no ProxyResolver is passed, then it is not
possible to use the system proxy resolver (since it is through ProxyResolver
that it would interact with either the system proxy resolver or the v8 one).

[sgurun-gerrit only, 2014/11/21 02:13:37]

Himm, there is some background to this. Android provides a local HTTP proxy that
does the proxying. This local HTTP proxy also reflects the PAC setting (if it is
set). Android proxy change intents broadcast the local host/port pair. 

I will update the comments to better explain this.

Because of this trick, PAC was actually working for Android webview in L
release.

+  builder.set_proxy_service(
+      net::ProxyService::CreateWithoutProxyResolver(
+          data_reduction_proxy_config_service_.release(),
+          net_log_.get()));
   builder.set_accept_language(net::HttpUtil::GenerateAcceptLanguageHeader(
       AwContentBrowserClient::GetAcceptLangsImpl()));
   builder.set_net_log(net_log_.get());
   builder.set_channel_id_enabled(false);
   ApplyCmdlineOverridesToURLRequestContextBuilder(&builder);
 
   url_request_context_.reset(builder.Build());
   // TODO(mnaganov): Fix URLRequestContextBuilder to use proper threads.
   net::HttpNetworkSession::Params network_session_params;
 
@@ skipping 70 matching lines @@
 net::NetLog* AwURLRequestContextGetter::GetNetLog() {
   return net_log_.get();
 }
 
 void AwURLRequestContextGetter::SetKeyOnIO(const std::string& key) {
   DCHECK(data_reduction_proxy_auth_request_handler_);
   data_reduction_proxy_auth_request_handler_->InitAuthentication(key);
 }
 
 }  // namespace android_webview