Move more Mojo bindings helpers out of internal namespace

mojo/public/cpp/bindings/lib/sync_handle_watcher.h

-// 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.
-
-#ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_SYNC_HANDLE_WATCHER_H_
-#define MOJO_PUBLIC_CPP_BINDINGS_LIB_SYNC_HANDLE_WATCHER_H_
-
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/threading/thread_checker.h"
-#include "mojo/public/cpp/bindings/sync_handle_registry.h"
-#include "mojo/public/cpp/system/core.h"
-
-namespace mojo {
-namespace internal {
-
-// SyncHandleWatcher supports watching a handle synchronously. It also supports
-// registering the handle with a thread-local storage (SyncHandleRegistry), so
-// that when other SyncHandleWatcher instances on the same thread perform sync
-// handle watching, this handle will be watched together.
-//
-// SyncHandleWatcher is used for sync methods. While a sync call is waiting for
-// response, we would like to block the thread. On the other hand, we need
-// incoming sync method requests on the same thread to be able to reenter. We
-// also need master interface endpoints to continue dispatching messages for
-// associated endpoints on different threads.
-//
-// This class is not thread safe.
-class SyncHandleWatcher {
- public:
-  // Note: |handle| must outlive this object.
-  SyncHandleWatcher(const Handle& handle,
-                    MojoHandleSignals handle_signals,
-                    const SyncHandleRegistry::HandleCallback& callback);
-
-  ~SyncHandleWatcher();
-
-  // Registers |handle_| with SyncHandleRegistry, so that when others perform
-  // sync handle watching on the same thread, |handle_| will be watched
-  // together.
-  void AllowWokenUpBySyncWatchOnSameThread();
-
-  // Waits on |handle_| plus all handles registered with SyncHandleRegistry and
-  // runs callbacks synchronously for those ready handles.
-  // This method:
-  //   - returns true when |should_stop| is set to true;
-  //   - return false when any error occurs, including this object being
-  //     destroyed during a callback.
-  bool SyncWatch(const bool* should_stop);
-
- private:
-  void IncrementRegisterCount();
-  void DecrementRegisterCount();
-
-  const Handle handle_;
-  const MojoHandleSignals handle_signals_;
-  SyncHandleRegistry::HandleCallback callback_;
-
-  // Whether |handle_| has been registered with SyncHandleRegistry.
-  bool registered_;
-  // If non-zero, |handle_| should be registered with SyncHandleRegistry.
-  size_t register_request_count_;
-
-  scoped_refptr<SyncHandleRegistry> registry_;
-
-  scoped_refptr<base::RefCountedData<bool>> destroyed_;
-
-  base::ThreadChecker thread_checker_;
-
-  DISALLOW_COPY_AND_ASSIGN(SyncHandleWatcher);
-};
-
-}  // namespace internal
-}  // namespace mojo
-
-#endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_SYNC_HANDLE_WATCHER_H_