Handle multiple modifications to distribution metrics correctly.
Give up trying to combine modifications into one - it's difficult with
distribution metrics where you can't just sum the deltas. Instead keep a list
of modifications and apply them all at once, in order.
This also does away with the confusing wrapper wrapper wrapper functions.
BUG=
Review URL: https://codereview.chromium.org/1531573003
Cr-Mirrored-From: https://chromium.googlesource.com/infra/infra
Cr-Mirrored-Commit: f208d8061b8aec3db4ef0084bab03f780133042a
4 files changed
