Provision to start base::SimpleTestTickClock at initial ticks

base/test/simple_test_tick_clock.cc

 // Copyright (c) 2012 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/simple_test_tick_clock.h"
 
 #include "base/logging.h"
 
 namespace base {
 
-SimpleTestTickClock::SimpleTestTickClock() {}
+SimpleTestTickClock::SimpleTestTickClock(TimeTicks initial)
+    : now_ticks_(initial) {}
 
 SimpleTestTickClock::~SimpleTestTickClock() {}
 
 TimeTicks SimpleTestTickClock::NowTicks() {
   AutoLock lock(lock_);
   return now_ticks_;
 }
 
 void SimpleTestTickClock::Advance(TimeDelta delta) {
   AutoLock lock(lock_);
   DCHECK(delta >= TimeDelta());
   now_ticks_ += delta;
 }
 
 }  // namespace base