Revert of Override rtc::Event with Chromium's implementation

third_party/webrtc_overrides/webrtc/rtc_base/event.h

-// Copyright 2017 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 THIRD_PARTY_WEBRTC_OVERRIDES_WEBRTC_RTC_BASE_EVENT_H_
-#define THIRD_PARTY_WEBRTC_OVERRIDES_WEBRTC_RTC_BASE_EVENT_H_
-
-#include "base/macros.h"
-#include "base/synchronization/waitable_event.h"
-
-namespace rtc {
-
-// Overrides WebRTC's internal event implementation to use Chromium's.
-class Event {
- public:
-  static const int kForever = -1;
-
-  Event(bool manual_reset, bool initially_signaled);
-  ~Event();
-
-  void Set();
-  void Reset();
-
-  // Wait for the event to become signaled, for the specified number of
-  // |milliseconds|.  To wait indefinetly, pass kForever.
-  bool Wait(int milliseconds);
-
- private:
-  base::WaitableEvent event_;
-  DISALLOW_IMPLICIT_CONSTRUCTORS(Event);
-};
-
-}  // namespace rtc
-
-#endif  // THIRD_PARTY_WEBRTC_OVERRIDES_WEBRTC_RTC_BASE_EVENT_H_