Cast: Add tests for clocks being slow/fast

media/cast/test/skewed_single_thread_task_runner.h

 // 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.
 
-#ifndef MEDIA_CAST_TEST_FAKE_TASK_RUNNER_H_
-#define MEDIA_CAST_TEST_FAKE_TASK_RUNNER_H_
+#ifndef MEDIA_CAST_TEST_SKEWED_TASK_RUNNER_H_
+#define MEDIA_CAST_TEST_SKEWED_TASK_RUNNER_H_
 
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/single_thread_task_runner.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "base/test/test_pending_task.h"
 
 namespace media {
 namespace cast {
 namespace test {
 
-typedef base::TestPendingTask PostedTask;
+// This class wraps a SingleThreadTaskRunner, and allows you to scale
+// the delay for any posted task by a factor. The factor is changed by
+// calling SetSkew(). A skew of 2.0 means that all delayed task will
+// have to wait twice as long.
+class SkewedSingleThreadTaskRunner : public base::SingleThreadTaskRunner {
+ public:
+  explicit SkewedSingleThreadTaskRunner(
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
 
-class FakeSingleThreadTaskRunner : public base::SingleThreadTaskRunner {
- public:
-  explicit FakeSingleThreadTaskRunner(base::SimpleTestTickClock* clock);
-
-  void RunTasks();
+  // Set the delay multiplier to |skew|.
+  void SetSkew(double skew);
 
   // base::SingleThreadTaskRunner implementation.
   virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
                                const base::Closure& task,
                                base::TimeDelta delay) OVERRIDE;
 
   virtual bool RunsTasksOnCurrentThread() const OVERRIDE;
 
   // This function is currently not used, and will return false.
   virtual bool PostNonNestableDelayedTask(
       const tracked_objects::Location& from_here,
       const base::Closure& task,
       base::TimeDelta delay) OVERRIDE;
 
  protected:
-  virtual ~FakeSingleThreadTaskRunner();
+  virtual ~SkewedSingleThreadTaskRunner();
 
  private:
-  base::SimpleTestTickClock* const clock_;
-  std::multimap<base::TimeTicks, PostedTask> tasks_;
+  double skew_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
-  DISALLOW_COPY_AND_ASSIGN(FakeSingleThreadTaskRunner);
+  DISALLOW_COPY_AND_ASSIGN(SkewedSingleThreadTaskRunner);
 };
 
 }  // namespace test
 }  // namespace cast
 }  // namespace media
 
-#endif  // MEDIA_CAST_TEST_FAKE_TASK_RUNNER_H_
+#endif  // MEDIA_CAST_TEST_SKEWED_TASK_RUNNER_H_