Add constexpr TaskTraits constructor.

base/task_scheduler/task_traits_unittest.cc

+// Copyright 2017 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 "base/task_scheduler/task_traits.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+
+TEST(TaskSchedulerTaskTraitsTest, Default) {
+  constexpr TaskTraits traits;
+  EXPECT_FALSE(traits.may_block());
+  EXPECT_FALSE(traits.with_base_sync_primitives());
+  EXPECT_EQ(TaskPriority::INHERITED, traits.priority());
+  EXPECT_EQ(TaskShutdownBehavior::SKIP_ON_SHUTDOWN, traits.shutdown_behavior());
+}
+
+TEST(TaskSchedulerTaskTraitsTest, MayBlock) {
+  constexpr TaskTraits traits = {MayBlock()};
+  EXPECT_TRUE(traits.may_block());
+  EXPECT_FALSE(traits.with_base_sync_primitives());
+  EXPECT_EQ(TaskPriority::INHERITED, traits.priority());
+  EXPECT_EQ(TaskShutdownBehavior::SKIP_ON_SHUTDOWN, traits.shutdown_behavior());
+}
+
+TEST(TaskSchedulerTaskTraitsTest, WithBaseSyncPrimitives) {
+  constexpr TaskTraits traits = {WithBaseSyncPrimitives()};
+  EXPECT_FALSE(traits.may_block());
+  EXPECT_TRUE(traits.with_base_sync_primitives());
+  EXPECT_EQ(TaskPriority::INHERITED, traits.priority());
+  EXPECT_EQ(TaskShutdownBehavior::SKIP_ON_SHUTDOWN, traits.shutdown_behavior());
+}
+
+TEST(TaskSchedulerTaskTraitsTest, TaskPriority) {
+  constexpr TaskTraits traits = {TaskPriority::USER_VISIBLE};
+  EXPECT_FALSE(traits.may_block());
+  EXPECT_FALSE(traits.with_base_sync_primitives());
+  EXPECT_EQ(TaskPriority::USER_VISIBLE, traits.priority());
+  EXPECT_EQ(TaskShutdownBehavior::SKIP_ON_SHUTDOWN, traits.shutdown_behavior());
+}
+
+TEST(TaskSchedulerTaskTraitsTest, TaskShutdownBehavior) {
+  constexpr TaskTraits traits = {TaskShutdownBehavior::BLOCK_SHUTDOWN};
+  EXPECT_FALSE(traits.may_block());
+  EXPECT_FALSE(traits.with_base_sync_primitives());
+  EXPECT_EQ(TaskPriority::INHERITED, traits.priority());
+  EXPECT_EQ(TaskShutdownBehavior::BLOCK_SHUTDOWN, traits.shutdown_behavior());
+}
+
+TEST(TaskSchedulerTaskTraitsTest, MultipleTraits) {
+  constexpr TaskTraits traits = {MayBlock(), WithBaseSyncPrimitives(),
+                                 TaskPriority::USER_VISIBLE,
+                                 TaskShutdownBehavior::BLOCK_SHUTDOWN};
+  EXPECT_TRUE(traits.may_block());
+  EXPECT_TRUE(traits.with_base_sync_primitives());
+  EXPECT_EQ(TaskPriority::USER_VISIBLE, traits.priority());
+  EXPECT_EQ(TaskShutdownBehavior::BLOCK_SHUTDOWN, traits.shutdown_behavior());
+}
+
+}  // namespace base