base: Factor task debug annotations out of MessageLoop

base/debug/task_annotator_unittest.cc

+// 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.
+
+#include "base/debug/task_annotator.h"
+#include "base/bind.h"
+#include "base/pending_task.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace debug {
+namespace {
+
+void TestTask(int* result) {
+  *result = 123;
+}
+
+}  // namespace
+
+TEST(TaskAnnotatorTest, QueueAndRunTask) {
+  int result = 0;
+  PendingTask pending_task(FROM_HERE, Bind(&TestTask, &result));
+
+  TaskAnnotator annotator;
+  annotator.DidQueueTask("TaskAnnotatorTest::Queue", pending_task);
+  EXPECT_EQ(0, result);
+  annotator.RunTask(
+      "TaskAnnotatorTest::Queue", "TaskAnnotatorTest::Run", pending_task);
+  EXPECT_EQ(123, result);
+}
+
+}  // namespace debug
+}  // namespace base