All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=821936

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=68fb259e73c8d5b9e16f2b0c9be3955a0d17e1206301d6072b583fd43a7c4680


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

android-nexus5
android-nexus7v2

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/1437ad76440000

😿 Pinpoint job stopped with an error.
https://pinpoint-dot-chromeperf.appspot.com/job/1437ad76440000

(WARNING) 2018-03-14 12:52:16,929 timeline_based_measurement._ComputeTimelineBasedMetrics:310  Starting to compute metrics on trace
(WARNING) 2018-03-14 12:52:43,007 timeline_based_measurement._ComputeTimelineBasedMetrics:316  Processing resulting traces took 26.077 seconds
Failure recorded: Error: Breakdown cannot be negative.
    at addIdleAndBlockByNetworkBreakdown_ (/tracing/metrics/system_health/breakdown_tree_helpers.html:215:13)
    at Object.generateWallClockTimeBreakdownTree (/tracing/metrics/system_health/breakdown_tree_helpers.html:252:5)
    at collectTimeToEvent (/tracing/metrics/system_health/loading_metric.html:151:43)
    at Object.collectLoadingMetricsForRenderer (/tracing/metrics/system_health/loading_metric.html:283:27)
    at Object.getInteractiveTimestamps (/tracing/extras/chrome/estimated_input_latency.html:45:37)
    at new expectedQueueingTimeMetric (/tracing/metrics/system_health/expected_queueing_time_metric.html:84:21)
    at runMetrics (/b/s/w/ir/third_party/catapult/tracing/tracing/metrics/metric_map_function.html:47:16)
    at metricMapFunction (/b/s/w/ir/third_party/catapult/tracing/tracing/metrics/metric_map_function.html:150:24)
    at Object.mapSingleTrace (/tracing/mre/map_single_trace.html:39:7)
    at eval (/b/s/w/ir/third_party/catapult/tracing/tracing/mre/map_single_trace_cmdline.html:61:18)

+benjhayden Any idea what's wrong here?

+dproy, Can you PTAL at this error in breakdown_tree_helpers?

KI. This CL got reverted: https://chromium-review.googlesource.com/c/catapult/+/961301

This regression has been open for half a year. It's not very actionable and the regression has been in all Chrome user's hands for months.