Add sanity test for CPU profiler

src/platform-openbsd.cc

Index: src/platform-openbsd.cc
diff --git a/src/platform-openbsd.cc b/src/platform-openbsd.cc
index e48d4cb35a477ece3168c76801a6edf4e3e379b5..f4d366bbdf3f942d1c372c6b7f50d1589144118b 100644
--- a/src/platform-openbsd.cc
+++ b/src/platform-openbsd.cc
@@ -529,7 +529,8 @@ class Thread::PlatformData : public Malloced {
 
 Thread::Thread(const Options& options)
     : data_(new PlatformData()),
-      stack_size_(options.stack_size()) {
+      stack_size_(options.stack_size()),
+      start_semaphore_(NULL) {
   set_name(options.name());
 }
 
@@ -551,7 +552,7 @@ static void* ThreadEntry(void* arg) {
 #endif
   thread->data()->thread_ = pthread_self();
   ASSERT(thread->data()->thread_ != kNoThread);
-  thread->Run();
+  thread->NotifyStartedAndRun();
   return NULL;
 }
 
@@ -827,7 +828,7 @@ class SignalSender : public Thread {
       // Start a thread that will send SIGPROF signal to VM threads,
       // when CPU profiling will be enabled.
       instance_ = new SignalSender(sampler->interval());
-      instance_->Start();
+      instance_->StartSynchronously();
     } else {
       ASSERT(instance_->interval_ == sampler->interval());
     }