[Draft] See what tests are broken.

mojo/public/cpp/system/watcher.cc

 // Copyright 2016 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.
 
 #include "mojo/public/cpp/system/watcher.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 54 matching lines @@
   return handle_.is_valid();
 }
 
 MojoResult Watcher::Start(Handle handle,
                           MojoHandleSignals signals,
                           const ReadyCallback& callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!IsWatching());
   DCHECK(!callback.is_null());
 
-  message_loop_observer_.reset(new MessageLoopObserver(this));
+  // message_loop_observer_.reset(new MessageLoopObserver(this));
   callback_ = callback;
   handle_ = handle;
   MojoResult result = MojoWatch(handle_.value(), signals,
                                 &Watcher::CallOnHandleReady,
                                 reinterpret_cast<uintptr_t>(this));
   if (result != MOJO_RESULT_OK) {
     handle_.set_value(kInvalidHandleValue);
     callback_.Reset();
     message_loop_observer_.reset();
     DCHECK(result == MOJO_RESULT_FAILED_PRECONDITION ||
@@ skipping 55 matching lines @@
     // default task runner for the IO thread.
     watcher->OnHandleReady(result);
   } else {
     watcher->task_runner_->PostTask(
         FROM_HERE,
         base::Bind(&Watcher::OnHandleReady, watcher->weak_self_, result));
   }
 }
 
 }  // namespace mojo