Add Directory.systemTemp getter to replace createSystemTemp().

sdk/lib/io/directory.dart

Index: sdk/lib/io/directory.dart
diff --git a/sdk/lib/io/directory.dart b/sdk/lib/io/directory.dart
index 6aa18f84c7aa22fe318e0fc4a225dc4124f695dc..80391d4e12257ce65fc691e8bea3e50c3b180560 100644
--- a/sdk/lib/io/directory.dart
+++ b/sdk/lib/io/directory.dart
@@ -68,59 +68,45 @@ abstract class Directory implements FileSystemEntity {
   void createSync({bool recursive: false});
 
   /**
-   * Creates a temporary directory in this directory.  Additional random
-   * characters are appended to [template] to produce a unique directory
-   * name.
+   * Gets the system temp directory.
+   *
+   * Gets the directory provided by the operating system for creating
+   * temporary files and directories in.
+   * The location of the system temp directory is platform-dependent,
+   * and may be set by an environment variable.
+   */
+  static Directory get systemTemp => _Directory.systemTemp;
+
+  /**
+   * Creates a temporary directory in this directory. Additional random
+   * characters are appended to [prefix] to produce a unique directory
+   * name. If [prefix] is missing or null, the empty string is used
+   * for [prefix].
    *
    * Returns a [:Future<Directory>:] that completes with the newly
    * created temporary directory.
    *
    * Deprecated behavior, to be removed Oct 18, 2013: If the path is the
    * empty string, the directory is created in the default system temp
-   * directory.  This capability has been moved to the static function
-   * [createSystemTemp].
+   * directory. This capability has been moved to the static getter
+   * [systemTemp].
    */
   Future<Directory> createTemp([String template]);
 
   /**
    * Synchronously creates a temporary directory in this directory.
-   * Additional random characters are appended to [template] to produce
-   * a unique directory name.
+   * Additional random characters are appended to [prefix] to produce
+   * a unique directory name. If [prefix] is missing or null, the empty
+   * string is used for [prefix].
    *
    * Returns the newly created temporary directory.
    *
    * Deprecated behavior, to be removed Oct 18, 2013: If the path is the
    * empty string, the directory is created in the default system temp
-   * directory.  This capability has been moved to the static function
+   * directory. This capability has been moved to the static function
    * [createSystemTemp].
    */
- Directory createTempSync([String template]);
-
-  /**
-   * Creates a temporary directory in the system temp directory.
-   * The location of the system temp directory is platform-dependent,
-   * and may be set by an environment variable.
-   * Additional random characters are appended to [template] to produce
-   * a unique directory name.
-   *
-   * Returns a [:Future<Directory>:] that completes with the newly
-   * created temporary directory.
-   */
-  static Future<Directory> createSystemTemp([String template]) =>
-      _Directory.createSystemTemp(template);
-
-  /**
-   * Synchronously creates a temporary directory in the system temp directory.
-   * The location of the system temp directory is platform-dependent,
-   * and may be set by an environment variable.
-   * Additional random characters are appended to [template] to produce
-   * a unique directory name.
-   *
-   * Returns a [:Future<Directory>:] that completes with the newly
-   * created temporary directory.
-   */
-  static Directory createSystemTempSync([String template]) =>
-      _Directory.createSystemTempSync(template);
+  Directory createTempSync([String template]);
 
   Future<String> resolveSymbolicLinks();