Reland old fix that was reverted without my knowledge.

content/common/hi_res_timer_manager_win.cc

 // Copyright (c) 2011 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 "content/common/hi_res_timer_manager.h"
 
 #include "base/time.h"
 
 HighResolutionTimerManager::HighResolutionTimerManager()
-    : hi_res_clock_used_(false) {
+    : hi_res_clock_available_(false) {
   ui::SystemMonitor* system_monitor = ui::SystemMonitor::Get();
   system_monitor->AddObserver(this);
   UseHiResClock(!system_monitor->BatteryPower());
 }
 
 HighResolutionTimerManager::~HighResolutionTimerManager() {
   ui::SystemMonitor::Get()->RemoveObserver(this);
   UseHiResClock(false);
 }
 
 void HighResolutionTimerManager::OnPowerStateChange(bool on_battery_power) {
   UseHiResClock(!on_battery_power);
 }
 
 void HighResolutionTimerManager::UseHiResClock(bool use) {
-  if (use == hi_res_clock_used_)
+  if (use == hi_res_clock_available_)
     return;
+  hi_res_clock_available_ = use;
   base::Time::EnableHighResolutionTimer(use);
 }