Make MojoWaitMany() accept zero handles.

mojo/public/js/core_unittests.js

 // 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.
 
 define([
     "gin/test/expect",
     "mojo/public/js/core",
     "gc",
   ], function(expect, core, gc) {
 
@@ skipping 60 matching lines @@
 
     expect(core.close(pipe.producerHandle)).toBe(core.RESULT_OK);
     expect(core.close(pipe.consumerHandle)).toBe(core.RESULT_OK);
   }
 
   function testNop(pipe) {
   }
 
   function testReadAndWriteMessage(pipe) {
     var wait = core.waitMany([], [], 0);
-    expect(wait.result).toBe(core.RESULT_INVALID_ARGUMENT);
+    expect(wait.result).toBe(core.RESULT_DEADLINE_EXCEEDED);
     expect(wait.index).toBe(null);
-    expect(wait.signalsState).toBe(null);
+    expect(wait.signalsState.length).toBe(0);
 
     wait = core.wait(pipe.handle0, core.HANDLE_SIGNAL_READABLE, 0);
     expect(wait.result).toBe(core.RESULT_DEADLINE_EXCEEDED);
     expect(wait.signalsState.satisfiedSignals).toBe(
            core.HANDLE_SIGNAL_WRITABLE);
     expect(wait.signalsState.satisfiableSignals).toBe(HANDLE_SIGNAL_ALL);
 
     wait = core.waitMany(
                   [pipe.handle0, pipe.handle1],
                   [core.HANDLE_SIGNAL_READABLE,core.HANDLE_SIGNAL_READABLE],
@@ skipping 94 matching lines @@
     expect(core.isHandle(pipe.handle1)).toBeTruthy();
     expect(core.isHandle(null)).toBeTruthy();
   }
 
   function testIsHandleDataPipe(pipe) {
     expect(core.isHandle(pipe.consumerHandle)).toBeTruthy();
     expect(core.isHandle(pipe.producerHandle)).toBeTruthy();
   }
 
 });