Update OperationSystem

增加新方法GameAsyncOperation.IsBusy()

Assets/YooAsset/Runtime/OperationSystem/GameAsyncOperation.cs

@@ -12,7 +12,22 @@ namespace YooAsset
 			OnUpdate();
 		}
 
+		/// <summary>
+		/// 异步操作开始
+		/// </summary>
 		protected abstract void OnStart();
+
+		/// <summary>
+		/// 异步操作更新
+		/// </summary>
 		protected abstract void OnUpdate();
+
+		/// <summary>
+		/// 异步操作系统是否繁忙
+		/// </summary>
+		protected bool IsBusy()
+		{
+			return OperationSystem.IsBusy;
+		}
 	}
 }