Add ability to clear pending tasks of TestMockTimeTaskRunner without running the tasks.

base/test/test_mock_time_task_runner.cc

 // 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.
 
 #include "base/test/test_mock_time_task_runner.h"
 
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/clock.h"
 #include "base/time/tick_clock.h"
@@ skipping 82 matching lines @@
 void TestMockTimeTaskRunner::RunUntilIdle() {
   DCHECK(thread_checker_.CalledOnValidThread());
   ProcessAllTasksNoLaterThan(TimeDelta());
 }
 
 void TestMockTimeTaskRunner::FastForwardUntilNoTasksRemain() {
   DCHECK(thread_checker_.CalledOnValidThread());
   ProcessAllTasksNoLaterThan(TimeDelta::Max());
 }
 
+void TestMockTimeTaskRunner::ClearPendingTasks() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  AutoLock scoped_lock(tasks_lock_);
+  while (!tasks_.empty())
+    tasks_.pop();
+}
+
 Time TestMockTimeTaskRunner::Now() const {
   DCHECK(thread_checker_.CalledOnValidThread());
   return now_;
 }
 
 TimeTicks TestMockTimeTaskRunner::NowTicks() const {
   DCHECK(thread_checker_.CalledOnValidThread());
   return now_ticks_;
 }
 
@@ skipping 89 matching lines @@
   if (!tasks_.empty() &&
       (tasks_.top().GetTimeToRun() - reference) <= max_delta) {
     *next_task = tasks_.top();
     tasks_.pop();
     return true;
   }
   return false;
 }
 
 }  // namespace base