update asset sytem

资源句柄类增加GetDownloadReport()方法。

Assets/YooAsset/Runtime/DownloadSystem/DownloadReport.cs

@@ -0,0 +1,30 @@
+
+namespace YooAsset
+{
+	public struct DownloadReport
+	{
+		/// <summary>
+		/// 下载进度（0f~1f）
+		/// </summary>
+		public float Progress;
+
+		/// <summary>
+		/// 需要下载的总字节数
+		/// </summary>
+		public long TotalSize;
+
+		/// <summary>
+		/// 已经下载的字节数
+		/// </summary>
+		public long DownloadedBytes;
+
+		public static DownloadReport CreateDefaultReport()
+		{
+			DownloadReport report = new DownloadReport();
+			report.Progress = 1f;
+			report.TotalSize = 0;
+			report.DownloadedBytes = 0;
+			return report;
+		}
+	}
+}