[libplatform] allow thread_pool_size to be > 4

src/libplatform/default-platform.h

Index: src/libplatform/default-platform.h
diff --git a/src/libplatform/default-platform.h b/src/libplatform/default-platform.h
index 8bdda95be67b5386ac49585dfd4de253da0181d0..7f539d3e5cdae0955e522c816ead630a0fe7c5eb 100644
--- a/src/libplatform/default-platform.h
+++ b/src/libplatform/default-platform.h
@@ -55,13 +55,14 @@ class DefaultPlatform : public Platform {
 
 
  private:
-  static const int kMaxThreadPoolSize;
+  static const int kDefaultThreadPoolSize;
 
   Task* PopTaskInMainThreadQueue(v8::Isolate* isolate);
   Task* PopTaskInMainThreadDelayedQueue(v8::Isolate* isolate);
 
   base::Mutex lock_;
   bool initialized_;
+  const int max_thread_pool_size_;
   int thread_pool_size_;
   std::vector<WorkerThread*> thread_pool_;
   TaskQueue queue_;