[logging] Quickfix for uninitialized timer in code-deopt event.

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index c4c11b8907e8099de454344b3d7e9e61c44921b0..8e8a1f912a1cfd19886f487cd4ea210b9f594a50 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -848,7 +848,9 @@ void Logger::CodeDeoptEvent(Code* code, DeoptKind kind, Address pc,
   if (!log_->IsEnabled()) return;
   Deoptimizer::DeoptInfo info = Deoptimizer::GetDeoptInfo(code, pc);
   Log::MessageBuilder msg(log_);
-  int since_epoch = static_cast<int>(timer_.Elapsed().InMicroseconds());
+  int since_epoch = timer_.IsStarted()
+                        ? static_cast<int>(timer_.Elapsed().InMicroseconds())
+                        : -1;
   msg.Append("code-deopt,%d,%d,", since_epoch, code->CodeSize());
   msg.AppendAddress(code->address());