[Autofill] Add typemap for autofill:FormFieldData and autofill::FormData.

components/autofill/content/public/interfaces/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//mojo/public/tools/bindings/mojom.gni")
 
 mojom("interfaces") {
   sources = [
     "autofill_agent.mojom",
     "autofill_driver.mojom",
   ]
+
+  public_deps = [
+    ":types",
+  ]
 }
+
+mojom("types") {
+  sources = [
+    "autofill_types.mojom",
+  ]
+
+  public_deps = [
+    "//url/mojo:url_mojom_gurl",
+  ]
+}
+
+mojom("test_types") {
+  sources = [
+    "test_autofill_types.mojom",
+  ]
+
+  public_deps = [
+    ":types",
+  ]
+}