Don't shadow variables (same name in scope)

base/threading/watchdog.cc

Index: base/threading/watchdog.cc
diff --git a/base/threading/watchdog.cc b/base/threading/watchdog.cc
index 82c187564b10a8694ba59dec0ed476a6cfdb6f7b..769119efc4b53b6383f1c3e9f2e067a44bda61d7 100644
--- a/base/threading/watchdog.cc
+++ b/base/threading/watchdog.cc
@@ -153,7 +153,7 @@ void Watchdog::ThreadDelegate::ThreadMain() {
     watchdog_->state_ = DISARMED;  // Only alarm at most once.
     TimeTicks last_alarm_time = TimeTicks::Now();
     {
-      AutoUnlock lock(watchdog_->lock_);
+      AutoUnlock unlock(watchdog_->lock_);
       watchdog_->Alarm();  // Set a break point here to debug on alarms.
     }
     TimeDelta last_alarm_delay = TimeTicks::Now() - last_alarm_time;