Domain Reliability: Add was_proxied field to beacons.

components/domain_reliability/beacon.cc

Index: components/domain_reliability/beacon.cc
diff --git a/components/domain_reliability/beacon.cc b/components/domain_reliability/beacon.cc
index 0d7abf7a920a68bdad572c2e5cdf04d55a2fa016..2a85c5384742b2325bdb192a765d5ab5c4f619ed 100644
--- a/components/domain_reliability/beacon.cc
+++ b/components/domain_reliability/beacon.cc
@@ -33,6 +33,7 @@ Value* DomainReliabilityBeacon::ToValue(
     beacon_value->Set("failure_data", failure_value);
   }
   beacon_value->SetString("server_ip", server_ip);
+  beacon_value->SetBoolean("was_proxied", was_proxied);
   beacon_value->SetString("protocol", protocol);
   if (http_response_code >= 0)
     beacon_value->SetInteger("http_response_code", http_response_code);