Remove some pointless log spewing.

sdk/lib/_internal/pub/lib/src/io.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Helper functionality to make working with IO easier.
 library pub.io;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
@@ skipping 200 matching lines @@
 void copyFile(String source, String destination) {
   writeBinaryFile(destination, readBinaryFile(source));
 }
 
 /// Creates a directory [dir].
 String createDir(String dir) {
   new Directory(dir).createSync();
   return dir;
 }
 
-/// Ensures that [dirPath] and all its parent directories exist. If they don't
+/// Ensures that [dir] and all its parent directories exist. If they don't
 /// exist, creates them.
-String ensureDir(String dirPath) {
-  log.fine("Ensuring directory $dirPath exists.");
-  var dir = new Directory(dirPath);
-  if (dirPath == '.' || dirExists(dirPath)) return dirPath;
-
-  ensureDir(path.dirname(dirPath));
-
-  try {
-    createDir(dirPath);
-  } on FileSystemException catch (ex) {
-    // Error 17 means the directory already exists (or 183 on Windows).
-    if (ex.osError.errorCode == 17 || ex.osError.errorCode == 183) {
-      log.fine("Got 'already exists' error when creating directory.");
-    } else {
-      throw ex;
-    }
-  }
-
-  return dirPath;
+String ensureDir(String dir) {
+  new Directory(dir).createSync(recursive: true);
+  return dir;
 }
 
 /// Creates a temp directory in [dir], whose name will be [prefix] with
 /// characters appended to it to make a unique name.
 /// Returns the path of the created directory.
 String createTempDir(String base, String prefix) {
   var tempDir = new Directory(base).createTempSync(prefix);
   log.io("Created temp directory ${tempDir.path}");
   return tempDir.path;
 }
@@ skipping 588 matching lines @@
   const PubProcessResult(this.stdout, this.stderr, this.exitCode);
 
   bool get success => exitCode == 0;
 }
 
 /// Gets a [Uri] for [uri], which can either already be one, or be a [String].
 Uri _getUri(uri) {
   if (uri is Uri) return uri;
   return Uri.parse(uri);
 }