Fix race in WebRtcVideoEngine2Tests, improve coverage.

webrtc/media/engine/fakewebrtcvideoengine.h

Index: webrtc/media/engine/fakewebrtcvideoengine.h
diff --git a/webrtc/media/engine/fakewebrtcvideoengine.h b/webrtc/media/engine/fakewebrtcvideoengine.h
index 2dce2c503fcf67e284ef0d3d84027a6dc7ffd74a..a223406a41ad7e7ae5a3c2caa95971b3b7f88892 100644
--- a/webrtc/media/engine/fakewebrtcvideoengine.h
+++ b/webrtc/media/engine/fakewebrtcvideoengine.h
@@ -199,8 +199,12 @@ class FakeWebRtcVideoEncoderFactory : public WebRtcVideoEncoderFactory {
     int64_t start_offset_ms = rtc::TimeMillis();
     int64_t wait_time = kEventTimeoutMs;
     do {
-      if (GetNumCreatedEncoders() >= num_encoders)
+      int num_created_encoders = GetNumCreatedEncoders();
+      if (num_created_encoders == num_encoders) {
         return true;
+      } else if (num_created_encoders > num_encoders) {
+        return false;
+      }
       wait_time = kEventTimeoutMs - (rtc::TimeMillis() - start_offset_ms);
     } while (wait_time > 0 && created_video_encoder_event_.Wait(wait_time));
     return false;