cc: Implement test task runner for tests.

cc/test/test_tile_task_runner.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 "cc/test/test_tile_task_runner.h"
+
+#include "base/logging.h"
+
+namespace cc {
+
+void TestTileTaskRunner::ProcessTask(TileTask* task) {
+  ScheduleTask(task);
+  RunTask(task);
+  CompleteTask(task);
+}
+
+void TestTileTaskRunner::ScheduleTask(TileTask* task) {
+  DCHECK(task);
+  task->state().DidSchedule();
+}
+
+void TestTileTaskRunner::CancelTask(TileTask* task) {
+  DCHECK(task);
+  task->state().DidCancel();
+}
+
+void TestTileTaskRunner::RunTask(TileTask* task) {
+  DCHECK(task);
+  task->state().DidStart();
+  task->RunOnWorkerThread();
+  task->state().DidFinish();
+}
+
+void TestTileTaskRunner::CompleteTask(TileTask* task) {
+  DCHECK(task);
+  DCHECK(task->state().IsFinished() || task->state().IsCanceled());
+  task->OnTaskCompleted();
+}
+
+}  // namespace cc