All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=627856

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0tqbuwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgkp3spQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0pDQsgoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgkqu7pQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgkquCoQkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0qmNogoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgks_VtAoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0pD-pwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgkq_4owoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0pCzrwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0umkuwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0vrhrQkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0vTWowoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0vTJsgoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0obnvgoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgkuuFsgkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0v6mrwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgkpuopwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgku_lqAoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0qv4rQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0qGDpQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg0siRtgkM


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

android-nexus5
android-nexus5X
android-nexus7v2
android-nexus9
chromium-rel-win10
chromium-rel-win7-gpu-ati
chromium-rel-win7-gpu-intel
chromium-rel-win7-gpu-nvidia
chromium-rel-win7-x64-dual
chromium-rel-win8-dual
linux-release
win-zenbook

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9007238273241230672

Looks like something which was merged into 5.3.345.2, but then recovered with later commits.