Go bindings: Don't import 'fmt' unless it is needed.

mojo/go/BUILD.gn

 # Copyright 2014 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("rules.gni")
+import("//mojo/public/tools/bindings/mojom.gni")
 
 go_library("application") {
   sources = [
     "//mojo/public/go/application/application_impl.go",
     "//mojo/public/go/application/connection.go",
   ]
   deps = [
     ":bindings",
     ":system",
   ]
@@ skipping 62 matching lines @@
       "tests/union_test.go",
       "tests/validation_test.go",
       "tests/validation_type_test.go",
     ]
     static_library_sources = [
       "c_embedder/c_embedder.cc",
       "c_embedder/c_embedder.h",
     ]
     deps = [
       ":application",
+      ":more_test_mojoms",
       ":platform_cgo",
       "//examples/echo",
       "//mojo/edk/base_edk",
       "//mojo/edk/system",
       "//mojo/public/interfaces/bindings/tests:test_interfaces",
     ]
   }
 }
+
+# These are additional test mojoms beyond those in the target
+# //mojo/public/interfaces/bindings/tests:test_interfaces.
+# These are built without 'generate_type_info = true' and so
+# allow us to test the go code generation in this mode also.
+mojom("more_test_mojoms") {
+  sources = [
+    "tests/test_enums.mojom",
+  ]
+}