Allow use of Mojo/V8 ProxyResolvers with URLRequestContextBuilder.

net/BUILD.gn

Index: net/BUILD.gn
diff --git a/net/BUILD.gn b/net/BUILD.gn
index 38bb647c147248addedbfb295e6247f863052d1a..01c56f4445816d2fce8b097c03323a6195ad0ddd 100644
--- a/net/BUILD.gn
+++ b/net/BUILD.gn
@@ -36,6 +36,7 @@ posix_avoid_mmap = is_android && current_cpu != "x86"
 
 use_v8_in_net = !is_ios && !is_proto_quic
 enable_built_in_dns = !is_ios && !is_proto_quic
+enable_net_mojo = !is_ios && !is_android && !is_proto_quic
 
 # True if certificates are represented with DER byte buffers. This can be true
 # in addition to use_openssl_certs or use_nss_certs, in that case byte certs
@@ -2492,6 +2493,8 @@ static_library("test_support") {
     "test/embedded_test_server/http_response.h",
     "test/embedded_test_server/request_handler_util.cc",
     "test/embedded_test_server/request_handler_util.h",
+    "test/embedded_test_server/simple_connection_listener.cc",
+    "test/embedded_test_server/simple_connection_listener.h",
     "test/event_waiter.h",
     "test/gtest_util.h",
     "test/net_test_suite.cc",
@@ -2634,7 +2637,7 @@ if (use_v8_in_net) {
   }
 }
 
-if (!is_ios && !is_android && !is_proto_quic) {
+if (enable_net_mojo) {
   source_set("net_browser_services") {
     sources = [
       "dns/mojo_host_resolver_impl.cc",
@@ -2678,6 +2681,33 @@ if (!is_ios && !is_android && !is_proto_quic) {
   }
 }
 
+if (use_v8_in_net) {
+  source_set("net_context_builder_with_v8") {
+    sources = [
+      "url_request/url_request_context_builder_v8.cc",
+      "url_request/url_request_context_builder_v8.h",
+    ]
+
+    defines = []
+
+    deps = [
+      ":net",
+      ":net_with_v8",
+      "//base",
+    ]
+
+    if (enable_net_mojo) {
+      deps += [
+        ":net_browser_services",
+        "//mojo/public/cpp/bindings",
+        "//net/interfaces",
+      ]
+
+      defines += [ "ENABLE_NET_MOJO" ]
+    }
+  }
+}
+
 if (!is_ios && !is_android) {
   executable("cert_verify_tool") {
     testonly = true
@@ -4557,6 +4587,8 @@ test("net_unittests") {
     "proxy/proxy_server_unittest.cc",
     "proxy/proxy_service_mojo_unittest.cc",
     "proxy/proxy_service_unittest.cc",
+    "proxy/test_mojo_proxy_resolver_factory.cc",
+    "proxy/test_mojo_proxy_resolver_factory.h",
     "quic/chromium/bidirectional_stream_quic_impl_unittest.cc",
     "quic/chromium/crypto/proof_test_chromium.cc",
     "quic/chromium/crypto/proof_verifier_chromium_test.cc",
@@ -4893,6 +4925,7 @@ test("net_unittests") {
     "url_request/url_fetcher_impl_unittest.cc",
     "url_request/url_fetcher_response_writer_unittest.cc",
     "url_request/url_request_context_builder_unittest.cc",
+    "url_request/url_request_context_builder_v8_unittest.cc",
     "url_request/url_request_context_unittest.cc",
     "url_request/url_request_data_job_unittest.cc",
     "url_request/url_request_file_dir_job_unittest.cc",
@@ -5152,21 +5185,27 @@ test("net_unittests") {
   }
 
   if (use_v8_in_net) {
-    deps += [ ":net_with_v8" ]
+    deps += [
+      ":net_context_builder_with_v8",
+      ":net_with_v8",
+    ]
   } else {
     sources -= [
       "proxy/proxy_resolver_v8_tracing_unittest.cc",
       "proxy/proxy_resolver_v8_tracing_wrapper_unittest.cc",
       "proxy/proxy_resolver_v8_unittest.cc",
+      "url_request/url_request_context_builder_v8_unittest.cc",
     ]
   }
 
-  if (use_v8_in_net && !is_android) {
+  if (enable_net_mojo) {
     deps += [
       ":net_browser_services",
       ":net_utility_services",
       "//mojo/edk/system",
     ]
+
+    defines += [ "ENABLE_NET_MOJO" ]
   } else {
     sources -= [
       "dns/host_resolver_mojo_unittest.cc",
@@ -5176,6 +5215,8 @@ test("net_unittests") {
       "proxy/mojo_proxy_resolver_v8_tracing_bindings_unittest.cc",
       "proxy/proxy_resolver_factory_mojo_unittest.cc",
       "proxy/proxy_service_mojo_unittest.cc",
+      "proxy/test_mojo_proxy_resolver_factory.cc",
+      "proxy/test_mojo_proxy_resolver_factory.h",
     ]
   }