Reland "Delete class EventTimerWrapper."

This is a reland of a421775a6d4f78f7aa9c3ea020a8834e049efbcc

Original change's description:
> Delete class EventTimerWrapper.
>
> Only user, iSACTest, refactored to use a sleep instead.
>
> Bug: webrtc:3380
> Change-Id: I683a5a05349f75a17e5d2a02d4a20a9cf059a28f
> Reviewed-on: https://webrtc-review.googlesource.com/96802
> Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
> Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
> Commit-Queue: Niels Moller <nisse@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#24541}

Tbr: henrik.lundin@webrtc.org
Bug: webrtc:3380
Change-Id: I541473b9c3ce2020f76d420598a7b10766f1d2a9
Reviewed-on: https://webrtc-review.googlesource.com/98481
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24620}
diff --git a/modules/audio_coding/test/iSACTest.cc b/modules/audio_coding/test/iSACTest.cc
index 009b76c..6a52042 100644
--- a/modules/audio_coding/test/iSACTest.cc
+++ b/modules/audio_coding/test/iSACTest.cc
@@ -27,7 +27,7 @@
 #include "modules/audio_coding/codecs/audio_format_conversion.h"
 #include "modules/audio_coding/test/utility.h"
 #include "rtc_base/strings/string_builder.h"
-#include "system_wrappers/include/event_wrapper.h"
+#include "system_wrappers/include/sleep.h"
 #include "test/testsupport/fileutils.h"
 
 namespace webrtc {
@@ -252,15 +252,19 @@
   _channel_B2A->ResetStats();
 
   char currentTime[500];
-  EventTimerWrapper* myEvent = EventTimerWrapper::Create();
-  EXPECT_TRUE(myEvent->StartTimer(true, 10));
+  int64_t time_ms = rtc::TimeMillis();
   while (!(_inFileA.EndOfFile() || _inFileA.Rewinded())) {
     Run10ms();
     _myTimer.Tick10ms();
     _myTimer.CurrentTimeHMS(currentTime);
 
     if ((adaptiveMode) && (_testMode != 0)) {
-      myEvent->Wait(5000);
+      time_ms += 10;
+      int64_t time_left_ms = time_ms - rtc::TimeMillis();
+      if (time_left_ms > 0) {
+        SleepMs(time_left_ms);
+      }
+
       EXPECT_TRUE(_acmA->SendCodec());
       EXPECT_TRUE(_acmB->SendCodec());
     }