Add a test for OptimizingCompileDispatcher::Flush's non-blocking behavior

src/compiler-dispatcher/optimizing-compile-dispatcher.h

Index: src/compiler-dispatcher/optimizing-compile-dispatcher.h
diff --git a/src/compiler-dispatcher/optimizing-compile-dispatcher.h b/src/compiler-dispatcher/optimizing-compile-dispatcher.h
index 7e081615174236acf0b4046874ef0c1a4fb88e97..5a9486d1771c81fbc7617de3c3a5947377c9999c 100644
--- a/src/compiler-dispatcher/optimizing-compile-dispatcher.h
+++ b/src/compiler-dispatcher/optimizing-compile-dispatcher.h
@@ -12,6 +12,7 @@
 #include "src/base/platform/mutex.h"
 #include "src/base/platform/platform.h"
 #include "src/flags.h"
+#include "src/globals.h"
 #include "src/list.h"
 
 namespace v8 {
@@ -20,7 +21,7 @@ namespace internal {
 class CompilationJob;
 class SharedFunctionInfo;
 
-class OptimizingCompileDispatcher {
+class V8_EXPORT_PRIVATE OptimizingCompileDispatcher {
  public:
   enum class BlockingBehavior { kBlock, kDontBlock };
 
@@ -38,9 +39,9 @@ class OptimizingCompileDispatcher {
 
   ~OptimizingCompileDispatcher();
 
-  void Run();
   void Stop();
   void Flush(BlockingBehavior blocking_behavior);
+  // Takes ownership of |job|.
   void QueueForOptimization(CompilationJob* job);
   void Unblock();
   void InstallOptimizedFunctions();