Fix a bug in pathToFileUri.

TBR

Review URL: https://codereview.chromium.org//14287003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/stack_trace@21916 260f80e4-7a28-3924-810f-c04153c831b5

pkgs/stack_trace/lib/src/utils.dart

diff --git a/pkgs/stack_trace/lib/src/utils.dart b/pkgs/stack_trace/lib/src/utils.dart
index ec764e5..50ccab3 100644
--- a/pkgs/stack_trace/lib/src/utils.dart
+++ b/pkgs/stack_trace/lib/src/utils.dart
@@ -30,7 +30,7 @@
   pathString = path.absolute(pathString);
   if (Platform.operatingSystem != 'windows') {
     return Uri.parse('file://$pathString');
-  } else if (path.rootPrefix(path).startsWith('\\\\')) {
+  } else if (path.rootPrefix(pathString).startsWith('\\\\')) {
     // Network paths become "file://hostname/path/to/file".
     return Uri.parse('file:${pathString.replaceAll("\\", "/")}');
   } else {