Add UMA metrics to log attachment broker errors.

ipc/attachment_broker_privileged_win.cc

Index: ipc/attachment_broker_privileged_win.cc
diff --git a/ipc/attachment_broker_privileged_win.cc b/ipc/attachment_broker_privileged_win.cc
index 77584cff1bd3380ce1fa7edccfd36c53edab7812..a283159171a4fc900023f63de64e50a29dff12bd 100644
--- a/ipc/attachment_broker_privileged_win.cc
+++ b/ipc/attachment_broker_privileged_win.cc
@@ -55,8 +55,10 @@ void AttachmentBrokerPrivilegedWin::OnDuplicateWinHandle(
   IPC::internal::HandleAttachmentWin::WireFormat wire_format =
       base::get<0>(param);
 
-  if (wire_format.destination_process == base::kNullProcessId)
+  if (wire_format.destination_process == base::kNullProcessId) {
+    LogError(NO_DESTINATION);
     return;
+  }
 
   HandleWireFormat new_wire_format =
       DuplicateWinHandle(wire_format, message.get_sender_pid());
@@ -82,6 +84,7 @@ void AttachmentBrokerPrivilegedWin::RouteDuplicatedHandle(
     // forever.
     LOG(ERROR) << "Failed to deliver brokerable attachment to process with id: "
                << dest;
+    LogError(DESTINATION_NOT_FOUND);
     return;
   }