Enable QUIC for proxies based on Finch config and command line switch.

net/url_request/url_request_context_builder.cc

Index: net/url_request/url_request_context_builder.cc
diff --git a/net/url_request/url_request_context_builder.cc b/net/url_request/url_request_context_builder.cc
index 303dd1761bfd0312645c30b2e2733390f233effe..e5d774a3ed653d1c0b959ad03059c7e6abdfb66e 100644
--- a/net/url_request/url_request_context_builder.cc
+++ b/net/url_request/url_request_context_builder.cc
@@ -185,7 +185,8 @@ URLRequestContextBuilder::HttpNetworkSessionParams::HttpNetworkSessionParams()
       testing_fixed_https_port(0),
       next_protos(NextProtosDefaults()),
       use_alternate_protocols(true),
-      enable_quic(false) {
+      enable_quic(false),
+      enable_quic_for_proxies(false) {
 }
 
 URLRequestContextBuilder::HttpNetworkSessionParams::~HttpNetworkSessionParams()
@@ -358,6 +359,8 @@ URLRequestContext* URLRequestContextBuilder::Build() {
       http_network_session_params_.trusted_spdy_proxy;
   network_session_params.next_protos = http_network_session_params_.next_protos;
   network_session_params.enable_quic = http_network_session_params_.enable_quic;
+  network_session_params.enable_quic_for_proxies =
+      http_network_session_params_.enable_quic_for_proxies;
   network_session_params.quic_connection_options =
       http_network_session_params_.quic_connection_options;