internal/proto: use ExtensionType TypeDescriptor method

Descriptor method renamed to TypeDescriptor.

Change-Id: I907169ba509395d079a95daecee53648969c9417
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/192140
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/go.mod b/go.mod
index 6eaf286..8e6fe74 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,4 @@
 
 go 1.9
 
-require google.golang.org/protobuf v0.0.0-20190820213257-f1e905b04207
+require google.golang.org/protobuf v0.0.0-20190828183429-79bfdbe45be2
diff --git a/go.sum b/go.sum
index 4c0044e..7f2cd56 100644
--- a/go.sum
+++ b/go.sum
@@ -8,6 +8,7 @@
 github.com/golang/protobuf v1.2.1-0.20190620192300-1ee46dfd80dd/go.mod h1:+CMAsi9jpYf/wAltLUKlg++CWXqxCJyD8iLDbQONsJs=
 github.com/golang/protobuf v1.2.1-0.20190806214225-7037721e6de0/go.mod h1:tDQPRlaHYu9yt1wPgdx85inRiLvUCuJZXsYjC0mwc1c=
 github.com/golang/protobuf v1.2.1-0.20190820204156-2da1b93405dd/go.mod h1:x87I3ou7ehf/yR6iQ88MkyDogdxXN04TELJ7HVy7V7I=
+github.com/golang/protobuf v1.2.1-0.20190820213554-ae1d65bc5435/go.mod h1:k7dGkiTZ3rjVDhKSpGt+x1zDzAePJk4jdhoBwIkQgBo=
 github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 google.golang.org/protobuf v0.0.0-20190514172829-e89e6244e0e8/go.mod h1:791zQGC15vDqjpmPRn1uGPu5oHy/Jzw/Q1n5JsgIIcY=
@@ -20,9 +21,9 @@
 google.golang.org/protobuf v0.0.0-20190620020611-d888139e7b59/go.mod h1:of3pt14Y+dOxz2tBOHXEoapPpKFC15/0zWhPAddkfsU=
 google.golang.org/protobuf v0.0.0-20190717230113-f647c82cc3c7 h1:U6U+Hb+UKNGJB0eMAjUGk0wTmy73kduTIvdsEgA4Gf8=
 google.golang.org/protobuf v0.0.0-20190717230113-f647c82cc3c7/go.mod h1:yGm7aNHn9Bp1NIvj6+CVUkcJshu+Usshfd3A+YxEuI8=
-google.golang.org/protobuf v0.0.0-20190808204900-1799d1111a45 h1:SZXAIsI6RiG0T8bAF4dqHDHgdqJtOa6tkofjswKtU20=
-google.golang.org/protobuf v0.0.0-20190808204900-1799d1111a45/go.mod h1:tRqhEyKwbKqwt5CQZAuOtj09RfhLNklDOhndhYA9blU=
 google.golang.org/protobuf v0.0.0-20190820203659-c0f8c0a24ece h1:AFYGmds8FWBGNw0zddlFiGtDvkVFSnQ7J2bAdH4X9Xk=
 google.golang.org/protobuf v0.0.0-20190820203659-c0f8c0a24ece/go.mod h1:tRqhEyKwbKqwt5CQZAuOtj09RfhLNklDOhndhYA9blU=
 google.golang.org/protobuf v0.0.0-20190820213257-f1e905b04207 h1:ulV4hvtdAg7XsymkxyxHtKYxQoSq88XU1bmtCELxG38=
 google.golang.org/protobuf v0.0.0-20190820213257-f1e905b04207/go.mod h1:UJqt2ZERO8/qk5A9t8Ujq6OJ+MNvOQpg9X4RKyYz9Ho=
+google.golang.org/protobuf v0.0.0-20190828183429-79bfdbe45be2 h1:g52BKWg08C9Z3iSV/mBCfoP+ObYXKCgdXF+p1EB9zD0=
+google.golang.org/protobuf v0.0.0-20190828183429-79bfdbe45be2/go.mod h1:fYMzYhnMXLj/kGDPzNOptS3IFFlQjWTlu2j3ZPET2lw=
diff --git a/internal/proto/registry.go b/internal/proto/registry.go
index 44d7090..af304e8 100644
--- a/internal/proto/registry.go
+++ b/internal/proto/registry.go
@@ -336,7 +336,7 @@
 		if xs == nil {
 			xs = make(extensionsByNumber)
 		}
-		xs[int32(xt.Descriptor().Number())] = protoimpl.X.ExtensionDescFromType(xt)
+		xs[int32(xt.TypeDescriptor().Number())] = protoimpl.X.ExtensionDescFromType(xt)
 		return true
 	})