All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=903355

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=3b69247e442573a55d63212b885c413869e752f0b36d93202800c7533b2de3ad


Bot(s) for this bug's original alert(s):

Android Nexus5 Perf
Android Nexus5X WebView Perf
Android Nexus6 WebView Perf

rendering.mobile - Benchmark documentation link:
  https://bit.ly/rendering-benchmarks

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/11563c93e40000

📍 Found significant differences after each of 4 commits.
https://pinpoint-dot-chromeperf.appspot.com/job/11563c93e40000

Reland "Enable Perfetto by default for all telemetry tests" by oysteine@chromium.org
https://chromium.googlesource.com/chromium/src/+/3bb24369bef996b43b2d2711f0033ba472f779ea
frame_times: 99.22 → No values

Perfetto: Fix for worker threads not finalizing proto packets by oysteine@google.com
https://chromium.googlesource.com/chromium/src/+/d420ce980291dbdee3d8a68594afbbfe5b75fbb4
frame_times: No values → 71.48

Parameterize some tests using kCompositorTouchAction by xidachen@chromium.org
https://chromium.googlesource.com/chromium/src/+/12592d437d9baa6ab3ec78e7ee48c1a98dff6c7d
frame_times: 70.56 → 69.45 (-1.11)

Allow safe search component to use custom API key by littlecvr@chromium.org
https://chromium.googlesource.com/chromium/src/+/cecd9afbd7813298763888547079ada50d675c5b
frame_times: 70.12 → 70.99 (+0.8691)

Understanding performance regressions:
  http://g.co/ChromePerformanceRegressions

Benchmark documentation link:
  https://bit.ly/rendering-benchmarks

The  thread_raster_cpu_time_per_frame here is very short, one thing Perfetto changes is that trace events on worker threads no longer grab the TraceLog lock and could make enough difference. The other two graphs look like they just stabilized a lot?

Comparing two traces from before/after, it looks like the raster events on the CompositorTileWorker and renderer main thread are much shorter now, but events on browser main thread and gpu thread are much longer. This really seems a bit strange. 

before: https://console.developers.google.com/m/cloudstorage/b/chrome-telemetry-output/o/analog_clock_svg_2018-10-29_05-35-09_7904.html
after : https://console.developers.google.com/m/cloudstorage/b/chrome-telemetry-output/o/analog_clock_svg_2018-11-02_15-42-53_95976.html