Fix typo and remove extra line break from TestMockTimeTaskRunner.

base/test/test_mock_time_task_runner.h

 // Copyright 2015 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 BASE_TEST_TEST_MOCK_TIME_TASK_RUNNER_H_
 #define BASE_TEST_TEST_MOCK_TIME_TASK_RUNNER_H_
 
 #include <queue>
 #include <vector>
 
@@ skipping 15 matching lines @@
 //
 // TestMockTimeTaskRunner has the following properties:
 //
 //   - Methods RunsTasksOnCurrentThread() and Post[Delayed]Task() can be called
 //     from any thread, but the rest of the methods must be called on the same
 //     thread the TaskRunner was created on.
 //   - It allows for reentrancy, in that it handles the running of tasks that in
 //     turn call back into it (e.g., to post more tasks).
 //   - Tasks are stored in a priority queue, and executed in the increasing
 //     order of post time + delay.
-//   - It does not check for overflow when doing time arithmetic``. A sufficient
+//   - It does not check for overflow when doing time arithmetic. A sufficient
 //     condition for preventing overflows is to make sure that the sum of all
 //     posted task delays and fast-forward increments is still representable by
 //     a TimeDelta, and that adding this delta to the starting values of Time
 //     and TickTime is still within their respective range.
 //   - Non-nestable tasks are not supported.
 //   - Tasks aren't guaranteed to be destroyed immediately after they're run.
 //
 // This is a slightly more sophisticated version of TestSimpleTaskRunner, in
 // that it supports running delayed tasks in the correct temporal order.
 class TestMockTimeTaskRunner : public SingleThreadTaskRunner {
@@ skipping 95 matching lines @@
   // |tasks_lock_| is held.
   TaskPriorityQueue tasks_;
   Lock tasks_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(TestMockTimeTaskRunner);
 };
 
 }  // namespace base
 
 #endif  // BASE_TEST_TEST_MOCK_TIME_TASK_RUNNER_H_