Default constructor for dart:io Path now handles native Windows paths. Path() now does the same as…

sdk/lib/_internal/dartdoc/bin/dartdoc.dart

Index: sdk/lib/_internal/dartdoc/bin/dartdoc.dart
diff --git a/sdk/lib/_internal/dartdoc/bin/dartdoc.dart b/sdk/lib/_internal/dartdoc/bin/dartdoc.dart
index 4a5dc1f1839d284b61f3f917222bdb939a929994..092da3375f8c9ece5627d503a3de7427d07d9d2d 100755
--- a/sdk/lib/_internal/dartdoc/bin/dartdoc.dart
+++ b/sdk/lib/_internal/dartdoc/bin/dartdoc.dart
@@ -117,7 +117,7 @@ main() {
         'omitted the files are generated into ./docs/',
       callback: (outDir) {
         if(outDir != null) {
-          dartdoc.outputDir = new Path.fromNative(outDir);
+          dartdoc.outputDir = new Path(outDir);
         }
       });
 
@@ -164,7 +164,7 @@ main() {
         'If omitted the package directory is the SDK pkg/ dir',
       callback: (pkgDir) {
         if(pkgDir != null) {
-          pkgPath = new Path.fromNative(pkgDir);
+          pkgPath = new Path(pkgDir);
         }
       });
 
@@ -185,7 +185,7 @@ main() {
     // If it is not, then we display a warning, as package imports might fail.
     var entrypointRoot;
     for(final arg in option.rest) {
-      var entrypoint = new Path.fromNative(arg);
+      var entrypoint = new Path(arg);
       entrypoints.add(entrypoint);
 
       if (entrypointRoot == null) {