Actually increment queue length for parallel recompile queue.

src/optimizing-compiler-thread.cc

Index: src/optimizing-compiler-thread.cc
diff --git a/src/optimizing-compiler-thread.cc b/src/optimizing-compiler-thread.cc
index e41c352f486624179e31d981e5d2bd6736d9ef6d..1cf0434fb768d6405e53e4dd463d1112d914f317 100644
--- a/src/optimizing-compiler-thread.cc
+++ b/src/optimizing-compiler-thread.cc
@@ -135,6 +135,8 @@ Handle<SharedFunctionInfo>
 
 void OptimizingCompilerThread::QueueForOptimization(
     OptimizingCompiler* optimizing_compiler) {
+  ASSERT(IsQueueAvailable());
+  Barrier_AtomicIncrement(&queue_length_, static_cast<Atomic32>(1));
   input_queue_.Enqueue(optimizing_compiler);
   input_queue_semaphore_->Signal();
 }