This is a high rate flaky failure.
Example log: https://pantheon.corp.google.com/storage/browser/chromeos-autotest-results/118873013-chromeos-test/chromeos4-row2-rack9-host1

05/20 07:40:12.092 DEBUG|             utils:0298| [stdout] [----------] 1 test from EncoderPerf/VideoEncodeAcceleratorTest
05/20 07:40:12.093 DEBUG|             utils:0298| [stdout] [ RUN      ] EncoderPerf/VideoEncodeAcceleratorTest.TestSimpleEncode/0
05/20 07:40:12.093 ERROR|             utils:0298| [stderr] libva info: VA-API version 0.39.2
05/20 07:40:12.097 ERROR|             utils:0298| [stderr] libva info: va_getDriverName() returns 0
05/20 07:40:12.100 ERROR|             utils:0298| [stderr] libva info: Trying to open /usr/lib64/va/drivers/i965_drv_video.so
05/20 07:40:12.104 ERROR|             utils:0298| [stderr] libva info: Found init function __vaDriverInit_0_39
05/20 07:40:12.107 ERROR|             utils:0298| [stderr] libva info: va_openDriver() returns 0
05/20 07:40:12.111 DEBUG|             utils:0298| [stdout] ../../../../../../../home/chrome-bot/chrome_root/src/media/gpu/video_encode_accelerator_unittest.cc:1459: Failure
05/20 07:40:12.111 DEBUG|             utils:0298| [stdout]       Expected: key_frame
05/20 07:40:12.111 DEBUG|             utils:0298| [stdout]       Which is: true
05/20 07:40:12.111 DEBUG|             utils:0298| [stdout] To be equal to: seen_keyframe_in_this_buffer_
05/20 07:40:12.112 DEBUG|             utils:0298| [stdout]       Which is: false