See the video captured when the PSNR went down to 22. There is some problem with flickering. 

Yiningc@, could you please see if this issue reproduces on the screen of the device both with and without HDMI output on. It could simply be an issue with the MHA cord we're using.

This was caught by AVABot.

average_psnr alert:
  device: samsung_galaxy_s3_verizon3
  reference_video: 480p30fpsH264_sports_sync.
  profile: chrome,fullscreen,mse,hdmi,.

  Before change: https://av-analysis.corp.google.com/#/get-testpass-details/2/VideoStack/357932
    median: 28.23.
    version: 61.0.3157.3
    date: 2017-07-15

  After change: https://av-analysis.corp.google.com/#/get-testpass-details/2/VideoStack/358784
    median: 22.035.
    version: 61.0.3157.3
    date: 2017-07-16