fix issue4 with timer

constraint_solver/constraint_solver.cc

@@ -1203,6 +1203,7 @@ Solver::Solver(const string& name)
   InitCachedIntConstants();  // to be called after the SENTINEL is set.
   InitCachedConstraint();  // Cache the true constraint.
   InitBoolVarCaches();
+  timer_->Restart();
 }
 
 Solver::~Solver() {

constraint_solver/search.cc

@@ -3213,6 +3213,7 @@ bool RegularLimit::CheckTime() {
   if (wall_time_ != kint64max && next_check_ <= check_count_) {
     Solver* const s = solver();
     int64 time_delta = s->wall_time() -  wall_time_offset_;
+    LOG(INFO) << "time delta = " << time_delta;
     if (smart_time_check_
         && check_count_ > kCheckWarmupIterations
         && time_delta > 0) {