Remove NaCl support.

src/base/platform/semaphore.cc

Index: src/base/platform/semaphore.cc
diff --git a/src/base/platform/semaphore.cc b/src/base/platform/semaphore.cc
index 7bf598662af4413bbca2199980ca36abc218d918..f6a518c9acb0e62a2b71869fea962c60ba9fc939 100644
--- a/src/base/platform/semaphore.cc
+++ b/src/base/platform/semaphore.cc
@@ -120,17 +120,6 @@ void Semaphore::Wait() {
 
 
 bool Semaphore::WaitFor(const TimeDelta& rel_time) {
-#if V8_OS_NACL
-  // PNaCL doesn't support sem_timedwait, do ugly busy waiting.
-  ElapsedTimer timer;
-  timer.Start();
-  do {
-    int result = sem_trywait(&native_handle_);
-    if (result == 0) return true;
-    DCHECK(errno == EAGAIN || errno == EINTR);
-  } while (!timer.HasExpired(rel_time));
-  return false;
-#else
   // Compute the time for end of timeout.
   const Time time = Time::NowFromSystemTime() + rel_time;
   const struct timespec ts = time.ToTimespec();
@@ -154,7 +143,6 @@ bool Semaphore::WaitFor(const TimeDelta& rel_time) {
     DCHECK_EQ(-1, result);
     DCHECK_EQ(EINTR, errno);
   }
-#endif
 }
 
 #elif V8_OS_WIN