Adjust a threshold in VP9 test.

For upcoming libvpx roll.

TBR=stefan@webrtc.org
BUG=

Review URL: https://webrtc-codereview.appspot.com/43799004

Cr-Commit-Position: refs/heads/master@{#8744}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8744 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/video_coding/codecs/test/videoprocessor_integrationtest.cc b/webrtc/modules/video_coding/codecs/test/videoprocessor_integrationtest.cc
index 53bf612..b1576a8 100644
--- a/webrtc/modules/video_coding/codecs/test/videoprocessor_integrationtest.cc
+++ b/webrtc/modules/video_coding/codecs/test/videoprocessor_integrationtest.cc
@@ -691,7 +691,7 @@
                      false, true, false);
   // Metrics for expected quality.
   QualityMetrics quality_metrics;
-  SetQualityMetrics(&quality_metrics, 31.5, 19.0, 0.80, 0.45);
+  SetQualityMetrics(&quality_metrics, 31.5, 18.0, 0.80, 0.45);
   // Metrics for rate control.
   RateControlMetrics rc_metrics[3];
   SetRateControlMetrics(rc_metrics, 0, 35, 50, 70, 15, 45, 0);