Allow Mojo structs as map keys

mojo/public/cpp/bindings/tests/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.
 
 source_set("tests") {
   testonly = true
 
   sources = [
     "array_common_test.h",
     "array_unittest.cc",
@@ skipping 76 matching lines @@
       "variant_test_util.h",
       "wtf_array_unittest.cc",
       "wtf_map_unittest.cc",
       "wtf_types_unittest.cc",
     ]
 
     deps = [
       "//mojo/public/cpp/bindings",
       "//mojo/public/cpp/system",
       "//mojo/public/interfaces/bindings/tests:test_interfaces",
+      "//mojo/public/interfaces/bindings/tests:test_interfaces_blink",
       "//mojo/public/interfaces/bindings/tests:test_wtf_types",
       "//mojo/public/interfaces/bindings/tests:test_wtf_types_blink",
       "//testing/gtest",
     ]
   }
 }
 
 source_set("struct_with_traits_impl") {
   sources = [
     "struct_with_traits_impl.cc",
@@ skipping 31 matching lines @@
 source_set("mojo_public_bindings_test_utils") {
   sources = [
     "validation_test_input_parser.cc",
     "validation_test_input_parser.h",
   ]
 
   deps = [
     "//mojo/public/c/system",
   ]
 }