Move EventWrapper class to target video_coding_legacy.

And remove some unneeded logic for WEBRTC_EVENT_INFINITE.

Bug: webrtc:3380
Change-Id: Ibf632493edc6ced1609bd9ced44c2020fe9878cf
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/169846
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30700}

modules/video_coding/event_wrapper.cc

@@ -0,0 +1,39 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "modules/video_coding/event_wrapper.h"
+
+#include "rtc_base/event.h"
+
+namespace webrtc {
+
+class EventWrapperImpl : public EventWrapper {
+ public:
+  ~EventWrapperImpl() override {}
+
+  bool Set() override {
+    event_.Set();
+    return true;
+  }
+
+  EventTypeWrapper Wait(int max_time_ms) override {
+    return event_.Wait(max_time_ms) ? kEventSignaled : kEventTimeout;
+  }
+
+ private:
+  rtc::Event event_;
+};
+
+// static
+EventWrapper* EventWrapper::Create() {
+  return new EventWrapperImpl();
+}
+
+}  // namespace webrtc