Consistently use setters to set event handlers in native APIs.

runtime/bin/process.dart

 // Copyright (c) 2011, 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.
 
 interface Process factory _Process {
   /*
    * Creates a new process object preparing to run the executable
    * found at [path] with the specified [arguments].
    */
   Process(String path, List<String> arguments);
@@ skipping 17 matching lines @@
   InputStream get stderr();
 
   /*
    * Returns an output stream to the process stdin.
    */
   OutputStream get stdin();
 
   /*
    * Sets an exit handler which gets invoked when the process terminates.
    */
-  void setExitHandler(void callback(int exitCode));
+  void set exitHandler(void callback(int exitCode));
 
   /*
    * Kills the process with [signal].
    */
   bool kill();
 
   /*
    * Terminates the streams and closes the exit handler of a process.
    */
   void close();
 }
 
 
 class ProcessException implements Exception {
   const ProcessException([String this.message, int this.errorCode = 0]);
   String toString() => "ProcessException: $message";
 
   /*
    * Contains the system message for the process exception if any.
    */
   final String message;
 
   /*
    * Contains the OS error code for the process exception if any.
    */
   final int errorCode;
 }