Dart: Moves |native| methods to patch files.

mojo/public/dart/src/handle_watcher.dart

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 part of core;
 
 class _MojoHandleWatcherNatives {
-  static int sendControlData(int controlHandle, int mojoHandle, SendPort port,
-      int data) native "MojoHandleWatcher_SendControlData";
-  static List recvControlData(int controlHandle) native
-      "MojoHandleWatcher_RecvControlData";
-  static int setControlHandle(int controlHandle) native
-      "MojoHandleWatcher_SetControlHandle";
-  static int getControlHandle() native "MojoHandleWatcher_GetControlHandle";
+  external static int sendControlData(int controlHandle, int mojoHandle,
+      SendPort port, int data);
+  external static List recvControlData(int controlHandle);
+  external static int setControlHandle(int controlHandle);
+  external static int getControlHandle();
 }
 
 // The MojoHandleWatcher sends a stream of events to application isolates that
 // register Mojo handles with it. Application isolates make the following calls:
 //
 // add(handle, port, signals) - Instructs the MojoHandleWatcher isolate to add
 //     'handle' to the set of handles it watches, and to notify the calling
 //     isolate only for the events specified by 'signals' using the send port
 //     'port'
 //
@@ skipping 311 matching lines @@
   }
 
   static MojoResult timer(Object ignored, SendPort port, int deadline) {
     // The deadline will be unwrapped before sending to the handle watcher.
     return _sendControlData(
         new MojoHandle(deadline),
         port,
         _encodeCommand(TIMER));
   }
 }