Add C++ wrappers for the wait set functions.

mojo/public/cpp/system/tests/core_unittest.cc

 // 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.
 
 // This file tests the C++ Mojo system core wrappers.
 // TODO(vtl): Maybe rename "CoreCppTest" -> "CoreTest" if/when this gets
 // compiled into a different binary from the C API tests.
 
 #include <stddef.h>
 
 #include <map>
 
 #include "mojo/public/cpp/system/buffer.h"
 #include "mojo/public/cpp/system/data_pipe.h"
 #include "mojo/public/cpp/system/handle.h"
 #include "mojo/public/cpp/system/macros.h"
 #include "mojo/public/cpp/system/message_pipe.h"
 #include "mojo/public/cpp/system/time.h"
 #include "mojo/public/cpp/system/wait.h"
+#include "mojo/public/cpp/system/wait_set.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace {
 
 TEST(CoreCppTest, GetTimeTicksNow) {
   const MojoTimeTicks start = GetTimeTicksNow();
   EXPECT_NE(static_cast<MojoTimeTicks>(0), start)
       << "GetTimeTicksNow should return nonzero value";
 }
@@ skipping 613 matching lines @@
   // Close the producer.
   ph.reset();
 
   // Waiting for "read" should now fail.
   EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
             Wait(ch.get(), MOJO_HANDLE_SIGNAL_READ_THRESHOLD, 1000, nullptr));
 }
 
 }  // namespace
 }  // namespace mojo