Also time other API functions calling into javascript.

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index 92b80542abdf9996bfe1c01849e93ae2a65fbef2..f20254f9167bc68250656cad2336440a0d06ede0 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -706,6 +706,7 @@ void Logger::SharedLibraryEvent(const wchar_t* library_path,
 
 
 void Logger::TimerEvent(const char* name, int64_t start, int64_t end) {
+  if (!log_->IsEnabled()) return;
   ASSERT(FLAG_log_timer_events);
   LogMessageBuilder msg(this);
   int since_epoch = static_cast<int>(start - epoch_);
@@ -715,6 +716,14 @@ void Logger::TimerEvent(const char* name, int64_t start, int64_t end) {
 }
 
 
+void Logger::TimerEventScope::LogTimerEvent() {
+  Logger* logger = isolate_->logger();
+  if (logger->is_logging()) {
+    logger->TimerEvent(name_, start_, OS::Ticks());
+  }
+}
+
+
 const char* Logger::TimerEventScope::v8_recompile_synchronous =
     "V8.RecompileSynchronous";
 const char* Logger::TimerEventScope::v8_recompile_parallel =