gRPC migration update

Change-Id: Icdd1a824948fa994cd36bd121c962f5ecf74e3cf
diff --git a/vendor/go.uber.org/zap/zapcore/marshaler.go b/vendor/go.uber.org/zap/zapcore/marshaler.go
index 2627a65..c3c55ba 100644
--- a/vendor/go.uber.org/zap/zapcore/marshaler.go
+++ b/vendor/go.uber.org/zap/zapcore/marshaler.go
@@ -23,6 +23,10 @@
 // ObjectMarshaler allows user-defined types to efficiently add themselves to the
 // logging context, and to selectively omit information which shouldn't be
 // included in logs (e.g., passwords).
+//
+// Note: ObjectMarshaler is only used when zap.Object is used or when
+// passed directly to zap.Any. It is not used when reflection-based
+// encoding is used.
 type ObjectMarshaler interface {
 	MarshalLogObject(ObjectEncoder) error
 }
@@ -39,6 +43,10 @@
 // ArrayMarshaler allows user-defined types to efficiently add themselves to the
 // logging context, and to selectively omit information which shouldn't be
 // included in logs (e.g., passwords).
+//
+// Note: ArrayMarshaler is only used when zap.Array is used or when
+// passed directly to zap.Any. It is not used when reflection-based
+// encoding is used.
 type ArrayMarshaler interface {
 	MarshalLogArray(ArrayEncoder) error
 }