TaskScheduler: Add SequenceToken and ScopedSetSequenceTokenForCurrentThread

base/sequence_token_unittest.cc

Index: base/sequence_token_unittest.cc
diff --git a/base/sequence_token_unittest.cc b/base/sequence_token_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c1585e21e10d5d1ab859b383595e1828c2b77412
--- /dev/null
+++ b/base/sequence_token_unittest.cc
@@ -0,0 +1,64 @@
+// 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 "base/sequence_token.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+
+TEST(SequenceTokenTest, IsValid) {
+  EXPECT_FALSE(SequenceToken().IsValid());
+  EXPECT_TRUE(SequenceToken::Create().IsValid());
+}
+
+TEST(SequenceTokenTest, OperatorEquals) {
+  const SequenceToken invalid_a;
+  const SequenceToken invalid_b;
+  const SequenceToken valid_a = SequenceToken::Create();
+  const SequenceToken valid_b = SequenceToken::Create();
+
+  EXPECT_FALSE(invalid_a == invalid_a);
+  EXPECT_FALSE(invalid_a == invalid_b);
+  EXPECT_FALSE(invalid_a == valid_a);
+  EXPECT_FALSE(invalid_a == valid_b);
+
+  EXPECT_FALSE(valid_a == invalid_a);
+  EXPECT_FALSE(valid_a == invalid_b);
+  EXPECT_EQ(valid_a, valid_a);
+  EXPECT_FALSE(valid_a == valid_b);
+}
+
+TEST(SequenceTokenTest, OperatorNotEquals) {
+  const SequenceToken invalid_a;
+  const SequenceToken invalid_b;
+  const SequenceToken valid_a = SequenceToken::Create();
+  const SequenceToken valid_b = SequenceToken::Create();
+
+  EXPECT_NE(invalid_a, invalid_a);
+  EXPECT_NE(invalid_a, invalid_b);
+  EXPECT_NE(invalid_a, valid_a);
+  EXPECT_NE(invalid_a, valid_b);
+
+  EXPECT_NE(valid_a, invalid_a);
+  EXPECT_NE(valid_a, invalid_b);
+  EXPECT_FALSE(valid_a != valid_a);
+  EXPECT_NE(valid_a, valid_b);
+}
+
+TEST(SequenceTokenTest, CurrentSequenceToken) {
+  const SequenceToken token = SequenceToken::Create();
+
+  EXPECT_FALSE(SequenceToken::GetCurrent().IsValid());
+
+  {
+    ScopedSetCurrentSequenceToken scoped_set_current_sequence_token(token);
+    EXPECT_TRUE(SequenceToken::GetCurrent().IsValid());
+    EXPECT_EQ(token, SequenceToken::GetCurrent());
+  }
+
+  EXPECT_FALSE(SequenceToken::GetCurrent().IsValid());
+}
+
+}  // namespace base