Comment and white-space cleanup in IO libraries.

runtime/bin/timer.dart

Index: runtime/bin/timer.dart
diff --git a/runtime/bin/timer.dart b/runtime/bin/timer.dart
index bb1f8854416ca44577c2cb0bb11498fff1333209..c5be36f040356c147854c5bfc1fd537d47ba12c3 100644
--- a/runtime/bin/timer.dart
+++ b/runtime/bin/timer.dart
@@ -3,13 +3,12 @@
 // BSD-style license that can be found in the LICENSE file.
 
 interface Timer default _Timer{
-
   /**
    * Creates a new timer. The [callback] callback is invoked after
    * [milliSeconds] milliseconds.
    */
   Timer(void callback(Timer timer), int milliSeconds);
- 
+
   /**
    * Creates a new repeating timer. The [callback] is invoked every
    * [milliSeconds] millisecond until cancelled.