Fix a bug with mojom imports where 2 imports with the same namespace would

mojo/public/bindings/tests/sample_import2.mojom

+// 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 "sample_import.mojom"
+
+module imported {
+
+// This sample adds more types and constants to the "imported" namespace,
+// to test a bug with importing multiple modules with the same namespace.
+
+enum Color {
+  COLOR_RED,
+  COLOR_BLACK,
+};
+
+struct Size {
+  int32 width;
+  int32 height;
+};
+
+struct Thing {
+  int32 shape;
+  int32 color;
+  Point location = {0, 0};
+  Size size;
+};
+
+}  // module imported