Reject some previuosly-escaped chars in hostnames.

net/base/filename_util_unittest.cc

Index: net/base/filename_util_unittest.cc
diff --git a/net/base/filename_util_unittest.cc b/net/base/filename_util_unittest.cc
index 16a6ec0c73d5fe598c14facf7a66c8d0c8bc4e6b..ef6b6e76d03167b08da6cf5fc572794f27a047ed 100644
--- a/net/base/filename_util_unittest.cc
+++ b/net/base/filename_util_unittest.cc
@@ -182,8 +182,8 @@ TEST(FilenameUtilTest, FileURLConversion) {
   const FileCase round_trip_cases[] = {
 #if defined(OS_WIN)
     {L"C:\\foo\\bar.txt", "file:///C:/foo/bar.txt"},
-    {L"\\\\some computer\\foo\\bar.txt",
-     "file://some%20computer/foo/bar.txt"},  // UNC
+    {L"\\\\some_computer\\foo\\bar.txt",
+     "file://some_computer/foo/bar.txt"},  // UNC
     {L"D:\\Name;with%some symbols*#",
      "file:///D:/Name%3Bwith%25some%20symbols*%23"},
     // issue 14153: To be tested with the OS default codepage other than 1252.