Use Mojo pipes to signal sync IPC events

mojo/public/cpp/bindings/lib/sync_handle_registry.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/bindings/lib/sync_handle_registry.h"
+#include "mojo/public/cpp/bindings/sync_handle_registry.h"
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/threading/thread_local.h"
 #include "mojo/public/c/system/core.h"
 
 namespace mojo {
-namespace internal {
 namespace {
 
 base::LazyInstance<base::ThreadLocalPointer<SyncHandleRegistry>>
     g_current_sync_handle_watcher = LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
 // static
 scoped_refptr<SyncHandleRegistry> SyncHandleRegistry::current() {
   scoped_refptr<SyncHandleRegistry> result(
@@ skipping 79 matching lines @@
 
   DCHECK(!g_current_sync_handle_watcher.Pointer()->Get());
   g_current_sync_handle_watcher.Pointer()->Set(this);
 }
 
 SyncHandleRegistry::~SyncHandleRegistry() {
   DCHECK(thread_checker_.CalledOnValidThread());
   g_current_sync_handle_watcher.Pointer()->Set(nullptr);
 }
 
-}  // namespace internal
 }  // namespace mojo