Implementation of ProxyResolver that uses a Mojo service.

BUG=11746

Review URL: https://codereview.chromium.org/917863005

Cr-Commit-Position: refs/heads/master@{#319848}
diff --git a/net/net.gypi b/net/net.gypi
index 796d43d..174ced83 100644
--- a/net/net.gypi
+++ b/net/net.gypi
@@ -1449,6 +1449,7 @@
       'proxy/proxy_config_unittest.cc',
       'proxy/proxy_info_unittest.cc',
       'proxy/proxy_list_unittest.cc',
+      'proxy/proxy_resolver_mojo_unittest.cc',
       'proxy/proxy_resolver_v8_tracing_unittest.cc',
       'proxy/proxy_resolver_v8_unittest.cc',
       'proxy/proxy_script_decider_unittest.cc',