Update from https://crrev.com/320343

base/test/test_mock_time_task_runner.h

Index: base/test/test_mock_time_task_runner.h
diff --git a/base/test/test_mock_time_task_runner.h b/base/test/test_mock_time_task_runner.h
index 5f06013cfa7e0253425fa329a687c50c3e19c176..c38fd6d9aca13c6f4a9a654bb0984b0ae6d5156d 100644
--- a/base/test/test_mock_time_task_runner.h
+++ b/base/test/test_mock_time_task_runner.h
@@ -61,6 +61,9 @@ class TestMockTimeTaskRunner : public SingleThreadTaskRunner {
   // elapse.
   void RunUntilIdle();
 
+  // Clears the queue of pending tasks without running them.
+  void ClearPendingTasks();
+
   // Returns the current virtual time (initially starting at the Unix epoch).
   Time Now() const;