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

third_party/webrtc_overrides/webrtc/rtc_base/event.cc

-// 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.
-
-#include "third_party/webrtc_overrides/webrtc/rtc_base/event.h"
-
-#include "base/time/time.h"
-
-namespace rtc {
-
-using base::WaitableEvent;
-
-Event::Event(bool manual_reset, bool initially_signaled)
-    : event_(manual_reset ? WaitableEvent::ResetPolicy::MANUAL
-                          : WaitableEvent::ResetPolicy::AUTOMATIC,
-             initially_signaled ? WaitableEvent::InitialState::SIGNALED
-                                : WaitableEvent::InitialState::NOT_SIGNALED) {}
-
-Event::~Event() {}
-
-void Event::Set() {
-  event_.Signal();
-}
-
-void Event::Reset() {
-  event_.Reset();
-}
-
-bool Event::Wait(int milliseconds) {
-  if (milliseconds == kForever) {
-    event_.Wait();
-    return true;
-  }
-
-  return event_.TimedWait(base::TimeDelta::FromMilliseconds(milliseconds));
-}
-
-}  // namespace rtc