Revert "Rename blahHandler to onBlah throughout dart:io."

runtime/bin/process_impl.dart

 // Copyright (c) 2012, 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.
 
 class _ProcessStartStatus {
   int _errorCode;  // Set to OS error code if process start failed.
   String _errorMessage;  // Set to OS error message if process start failed.
 }
 
 
@@ skipping 26 matching lines @@
     }
     _workingDirectory = workingDirectory;
 
     _in = new _Socket._internalReadOnly();  // stdout coming from process.
     _out = new _Socket._internalWriteOnly();  // stdin going to process.
     _err = new _Socket._internalReadOnly();  // stderr coming from process.
     _exitHandler = new _Socket._internalReadOnly();
     _closed = false;
     _killed = false;
     _started = false;
-    _onExit = null;
+    _exitHandlerCallback = null;
     // TODO(ager): Make the actual process starting really async instead of
     // simulating it with a timer.
     new Timer((Timer ignore) => start(), 0);
   }
 
   int _intFromBytes(List<int> bytes, int offset) {
     return (bytes[offset] +
             (bytes[offset + 1] << 8) +
             (bytes[offset + 2] << 16) +
             (bytes[offset + 3] << 24));
   }
 
   void start() {
     var status = new _ProcessStartStatus();
     bool success = _start(_path,
                           _arguments,
                           _workingDirectory,
                           _in,
                           _out,
                           _err,
                           _exitHandler,
                           status);
     if (!success) {
       close();
-      if (_onError !== null) {
-        _onError(new ProcessException(status._errorMessage, status._errorCode));
+      if (_errorHandler !== null) {
+        _errorHandler(new ProcessException(status._errorMessage,
+                                           status._errorCode));
         return;
       }
     }
     _started = true;
 
     // Make sure to activate socket handlers now that the file
     // descriptors have been set.
     _in._activateHandlers();
     _out._activateHandlers();
     _err._activateHandlers();
 
     // Setup an exit handler to handle internal cleanup and possible
     // callback when a process terminates.
     int exitDataRead = 0;
     final int EXIT_DATA_SIZE = 8;
     List<int> exitDataBuffer = new List<int>(EXIT_DATA_SIZE);
-    _exitHandler.inputStream.onData = () {
+    _exitHandler.inputStream.dataHandler = () {
 
       int exitCode(List<int> ints) {
         var code = _intFromBytes(ints, 0);
         var negative = _intFromBytes(ints, 4);
         assert(negative == 0 || negative == 1);
         return (negative == 0) ? code : -code;
       }
 
       void handleExit() {
-        if (_onExit !== null) {
-          _onExit(exitCode(exitDataBuffer));
+        if (_exitHandlerCallback !== null) {
+          _exitHandlerCallback(exitCode(exitDataBuffer));
         }
       }
 
       exitDataRead += _exitHandler.inputStream.readInto(
           exitDataBuffer, exitDataRead, EXIT_DATA_SIZE - exitDataRead);
       if (exitDataRead == EXIT_DATA_SIZE) handleExit();
     };
 
-    if (_onStart !== null) {
-      _onStart();
+    if (_startHandler !== null) {
+      _startHandler();
     }
   }
 
   bool _start(String path,
               List<String> arguments,
               String workingDirectory,
               Socket input,
               Socket output,
               Socket error,
               Socket exitHandler,
@@ skipping 15 matching lines @@
 
   OutputStream get stdin() {
     if (_closed) {
       throw new ProcessException("Process closed");
     }
     return _out.outputStream;
   }
 
   void kill() {
     if (_closed && _pid === null) {
-      if (_onError !== null) {
-        _onError(new ProcessException("Process closed"));
+      if (_errorHandler !== null) {
+        _errorHandler(new ProcessException("Process closed"));
       }
       return;
     }
     if (_killed) {
       return;
     }
     // TODO(ager): Make the actual kill operation asynchronous.
     if (_kill(_pid)) {
       _killed = true;
       return;
     }
-    if (_onError !== null) {
-      _onError(new ProcessException("Could not kill process"));
+    if (_errorHandler !== null) {
+      _errorHandler(new ProcessException("Could not kill process"));
       return;
     }
   }
 
   void _kill(int pid) native "Process_Kill";
 
   void close() {
     if (_closed) {
       throw new ProcessException("Process closed");
     }
     _in.close();
     _out.close();
     _err.close();
     _exitHandler.close();
     _closed = true;
   }
 
-  void set onExit(void callback(int exitCode)) {
+  void set exitHandler(void callback(int exitCode)) {
     if (_closed) {
       throw new ProcessException("Process closed");
     }
     if (_killed) {
       throw new ProcessException("Process killed");
     }
-    _onExit = callback;
+    _exitHandlerCallback = callback;
   }
 
-  void set onError(void callback(ProcessException exception)) {
-    _onError = callback;
+  void set errorHandler(void callback(ProcessException exception)) {
+    _errorHandler = callback;
   }
 
-  void set onStart(void callback()) {
-    _onStart = callback;
+  void set startHandler(void callback()) {
+    _startHandler = callback;
   }
 
   String _path;
   ObjectArray<String> _arguments;
   String _workingDirectory;
   Socket _in;
   Socket _out;
   Socket _err;
   Socket _exitHandler;
   int _pid;
   bool _closed;
   bool _killed;
   bool _started;
-  Function _onExit;
-  Function _onError;
-  Function _onStart;
+  Function _exitHandlerCallback;
+  Function _errorHandler;
+  Function _startHandler;
 }