Add sanity test for CPU profiler

src/platform-cygwin.cc

Index: src/platform-cygwin.cc
diff --git a/src/platform-cygwin.cc b/src/platform-cygwin.cc
index 67c389e794eca914d0ff9259e10903b5289dff25..23f88c9fe6c883c1615301436f500e87d5f2e465 100644
--- a/src/platform-cygwin.cc
+++ b/src/platform-cygwin.cc
@@ -381,7 +381,8 @@ 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());
 }
 
@@ -398,7 +399,7 @@ static void* ThreadEntry(void* arg) {
   // one) so we initialize it here too.
   thread->data()->thread_ = pthread_self();
   ASSERT(thread->data()->thread_ != kNoThread);
-  thread->Run();
+  thread->NotifyStartedAndRun();
   return NULL;
 }
 
@@ -639,7 +640,7 @@ class SamplerThread : public Thread {
     SamplerRegistry::AddActiveSampler(sampler);
     if (instance_ == NULL) {
       instance_ = new SamplerThread(sampler->interval());
-      instance_->Start();
+      instance_->StartSynchronously();
     } else {
       ASSERT(instance_->interval_ == sampler->interval());
     }