Update //third_party/protobuf to version 3.

third_party/protobuf/examples/add_person_test.go

+package main
+
+import (
+        "strings"
+        "testing"
+
+        "github.com/golang/protobuf/proto"
+        pb "github.com/google/protobuf/examples/tutorial"
+)
+
+func TestPromptForAddressReturnsAddress(t *testing.T) {
+        in := `12345
+Example Name
+name@example.com
+123-456-7890
+home
+222-222-2222
+mobile
+111-111-1111
+work
+777-777-7777
+unknown
+
+`
+        got, err := promptForAddress(strings.NewReader(in))
+        if err != nil {
+                t.Fatalf("promptForAddress(%q) had unexpected error: %s", in, err.Error())
+        }
+        if got.Id != 12345 {
+                t.Errorf("promptForAddress(%q) got %d, want ID %d", in, got.Id, 12345)
+        }
+        if got.Name != "Example Name" {
+                t.Errorf("promptForAddress(%q) => want name %q, got %q", "Example Name", got.Name)
+        }
+        if got.Email != "name@example.com" {
+                t.Errorf("promptForAddress(%q) => want email %q, got %q", "name@example.com", got.Email)
+        }
+
+        want := []*pb.Person_PhoneNumber{
+                {Number: "123-456-7890", Type: pb.Person_HOME},
+                {Number: "222-222-2222", Type: pb.Person_MOBILE},
+                {Number: "111-111-1111", Type: pb.Person_WORK},
+                {Number: "777-777-7777", Type: pb.Person_MOBILE},
+        }
+        if len(got.Phones) != len(want) {
+                t.Errorf("want %d phone numbers, got %d", len(want), len(got.Phones))
+        }
+        phones := len(got.Phones)
+        if phones > len(want) {
+                phones = len(want)
+        }
+        for i := 0; i < phones; i++ {
+                if !proto.Equal(got.Phones[i], want[i]) {
+                        t.Errorf("want phone %q, got %q", *want[i], *got.Phones[i])
+                }
+
+        }
+}