Revert "Fix remaining strong-mode warnings and errors in dart:io."

sdk/lib/io/directory_impl.dart

Index: sdk/lib/io/directory_impl.dart
diff --git a/sdk/lib/io/directory_impl.dart b/sdk/lib/io/directory_impl.dart
index c1fc540c52958929299e98e68f6314a51e1494b6..52cf54824ecf4e8ed14a4b5491ade076c4a32471 100644
--- a/sdk/lib/io/directory_impl.dart
+++ b/sdk/lib/io/directory_impl.dart
@@ -72,6 +72,30 @@ class _Directory extends FileSystemEntity implements Directory {
 
   FileStat statSync() => FileStat.statSync(path);
 
+  // Compute the index of the first directory in the list that exists. If
+  // none of the directories exist dirsToCreate.length is returned.
+  Future<int> _computeExistingIndex(List dirsToCreate) {
+    var future;
+    var notFound = dirsToCreate.length;
+    for (var i = 0; i < dirsToCreate.length; i++) {
+      if (future == null) {
+        future = dirsToCreate[i].exists().then((e) => e ? i : notFound);
+      } else {
+        future = future.then((index) {
+          if (index != notFound) {
+            return new Future.value(index);
+          }
+          return dirsToCreate[i].exists().then((e) => e ? i : notFound);
+        });
+      }
+    }
+    if (future == null) {
+      return new Future.value(notFound);
+    } else {
+      return future;
+    }
+  }
+
   Future<Directory> create({bool recursive: false}) {
     if (recursive) {
       return exists().then((exists) {
@@ -256,7 +280,7 @@ class _AsyncDirectoryLister {
   final bool recursive;
   final bool followLinks;
 
-  StreamController<FileSystemEntity> controller;
+  StreamController controller;
   bool canceled = false;
   bool nextRunning = false;
   bool closed = false;
@@ -264,10 +288,10 @@ class _AsyncDirectoryLister {
   Completer closeCompleter = new Completer();
 
   _AsyncDirectoryLister(this.path, this.recursive, this.followLinks) {
-    controller = new StreamController<FileSystemEntity>(onListen: onListen,
-                                                        onResume: onResume,
-                                                        onCancel: onCancel,
-                                                        sync: true);
+    controller = new StreamController(onListen: onListen,
+                                      onResume: onResume,
+                                      onCancel: onCancel,
+                                      sync: true);
   }
 
   // Calling this function will increase the reference count on the native
@@ -278,7 +302,7 @@ class _AsyncDirectoryLister {
     return (_ops == null) ? null : _ops.getPointer();
   }
 
-  Stream<FileSystemEntity> get stream => controller.stream;
+  Stream get stream => controller.stream;
 
   void onListen() {
     _IOService._dispatch(_DIRECTORY_LIST_START, [path, recursive, followLinks])