goprotobuf: Remove an incorrect sentence in the GetExtension doc comment.
R=r
CC=golang-codereviews
https://codereview.appspot.com/51010043
diff --git a/proto/extensions.go b/proto/extensions.go
index 50d72aa..c40b392 100644
--- a/proto/extensions.go
+++ b/proto/extensions.go
@@ -222,8 +222,6 @@
// GetExtension parses and returns the given extension of pb.
// If the extension is not present it returns ErrMissingExtension.
-// If the returned extension is modified, SetExtension must be called
-// for the modifications to be reflected in pb.
func GetExtension(pb extendableProto, extension *ExtensionDesc) (interface{}, error) {
if err := checkExtensionTypes(pb, extension); err != nil {
return nil, err
