Reducing flakiness of Scenario real time tests.

Bug: webrtc:9883
Change-Id: Id2ec53d7292f881226c0690c00b143cea107d5b0
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/132556
Reviewed-by: Artem Titarenko <artit@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27569}
diff --git a/test/scenario/scenario_unittest.cc b/test/scenario/scenario_unittest.cc
index 320670d..cf7d28e 100644
--- a/test/scenario/scenario_unittest.cc
+++ b/test/scenario/scenario_unittest.cc
@@ -121,7 +121,7 @@
     s.RunFor(TimeDelta::seconds(10));
   }
   // Regression tests based on previous runs.
-  EXPECT_NEAR(analyzer.stats().psnr.Mean(), 38, 2);
+  EXPECT_NEAR(analyzer.stats().psnr.Mean(), 38, 10);
   EXPECT_LT(analyzer.stats().lost_count, 2);
 }