Mojo: Support enums as map keys in WTF

mojo/public/cpp/bindings/tests/wtf_hash_unittest.cc

 // 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.
 
 #include "mojo/public/cpp/bindings/lib/wtf_hash_util.h"
 
 #include "mojo/public/interfaces/bindings/tests/test_structs.mojom-blink.h"
+#include "mojo/public/interfaces/bindings/tests/test_wtf_types.mojom-blink.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/WebKit/Source/wtf/HashFunctions.h"
 
 namespace mojo {
 namespace test {
 namespace {
 
 using WTFHashTest = testing::Test;
 
 TEST_F(WTFHashTest, NestedStruct) {
   // Just check that this template instantiation compiles.
   ASSERT_EQ(::mojo::internal::Hash(
                 ::mojo::internal::kHashSeed,
                 blink::SimpleNestedStruct::New(blink::ContainsOther::New(1))),
             ::mojo::internal::Hash(
                 ::mojo::internal::kHashSeed,
                 blink::SimpleNestedStruct::New(blink::ContainsOther::New(1))));
 }
 
 TEST_F(WTFHashTest, UnmappedNativeStruct) {
   // Just check that this template instantiation compiles.
   ASSERT_EQ(::mojo::internal::Hash(::mojo::internal::kHashSeed,
                                    blink::UnmappedNativeStruct::New()),
             ::mojo::internal::Hash(::mojo::internal::kHashSeed,
                                    blink::UnmappedNativeStruct::New()));
 }
 
+TEST_F(WTFHashTest, Enum) {
+  // Just check that this template instantiation compiles.
+
+  // Top-level.
+  ASSERT_EQ(WTF::DefaultHash<blink::TopLevelEnum>::Hash().hash(
+                blink::TopLevelEnum::E0),
+            WTF::DefaultHash<blink::TopLevelEnum>::Hash().hash(
+                blink::TopLevelEnum::E0));
+
+  // Nested in struct.
+  ASSERT_EQ(WTF::DefaultHash<blink::TestWTFStruct::NestedEnum>::Hash().hash(
+                blink::TestWTFStruct::NestedEnum::E0),
+            WTF::DefaultHash<blink::TestWTFStruct::NestedEnum>::Hash().hash(
+                blink::TestWTFStruct::NestedEnum::E0));
+
+  // Nested in interface.
+  ASSERT_EQ(WTF::DefaultHash<blink::TestWTF::NestedEnum>::Hash().hash(
+                blink::TestWTF::NestedEnum::E0),
+            WTF::DefaultHash<blink::TestWTF::NestedEnum>::Hash().hash(
+                blink::TestWTF::NestedEnum::E0));
+}
+
 }  // namespace
 }  // namespace test
 }  // namespace mojo