Stats updater uses wrong timestamps

[iefremov]

https://github.com/brave/brave-core/blob/master/browser/brave_stats_updater_params.cc#L17

Here we cache base::Time::Now() on startup and then use it in all outgoing pings. This way, all stats updater pings contain the same timestamp until the browser restart.

It would be more precise to take the actual Now() every time.

Brave | 0.64.2 Chromium: 73.0.3683.75 (Developer Build) (64-bit)

[iefremov]

@bbondy @too4words @aekeus JFYI

[iefremov]

Also there is a possible underflow: https://github.com/brave/brave-core/blob/master/browser/brave_stats_updater_params.cc#L98

(day_of_week can be zero if it is Sunday)

[emerick]

I guess I ported this bug right over from Muon, oops: https://github.com/brave/browser-laptop/blob/8692beec44ff4a0a7c56b5ba004bc6ea75365ccf/app/dates.js#L42

[btlechowski]

Verification passed on

Brave	0.62.49 Chromium: 73.0.3683.86 (Official Build) (64-bit)
Revision	f9b0bec6063ea50ce2b71f5b9abbae7beee319a6-refs/branch-heads/3683@{#858}
OS	Windows 10 OS Build 17134.523

Used test plan from brave/brave-core#2112
Clean install ping on 2019-04-01
https://laptop-updates.brave.com/1/usage/brave-core?platform=winx64-bc&channel=release&version=0.62.49&daily=true&weekly=true&monthly=true&first=true&woi=2019-04-01&ref=none
Ping on 2019-04-02
https://laptop-updates.brave.com/1/usage/brave-core?platform=winx64-bc&channel=release&version=0.62.49&daily=true&weekly=false&monthly=false&first=false&woi=2019-04-01&ref=none

Verified passed with

Brave	0.62.49 Chromium: 73.0.3683.86 (Official Build) (64-bit)
Revision	f9b0bec6063ea50ce2b71f5b9abbae7beee319a6-refs/branch-heads/3683@{#858}
OS	Mac OS X

• Verified with test plan from Stats updater fixes brave-core#2112 (launched with --enable-logging=stderr --v=1)

Initial ping:
[34560:775:0402/120420.690210:VERBOSE1:brave_stats_updater.cc(157)] Brave stats ping, url: https://laptop-updates.brave.com/1/usage/brave-core?platform=osx-bc&channel=release&version=0.62.49&daily=true&weekly=true&monthly=true&first=true&woi=2019-04-01&ref=none

"Next Day" ping:
[34639:775:0403/131315.015755:VERBOSE1:brave_stats_updater.cc(157)] Brave stats ping, url: https://laptop-updates.brave.com/1/usage/brave-core?platform=osx-bc&channel=release&version=0.62.49&daily=true&weekly=false&monthly=false&first=false&woi=2019-04-01&ref=none

Verification passed on

Brave	0.62.50 Chromium: 73.0.3683.86 (Official Build) (64-bit)
Revision	f9b0bec6063ea50ce2b71f5b9abbae7beee319a6-refs/branch-heads/3683@{#858}
OS	Linux

• Verified with test plan from Stats updater fixes brave-core#2112 (launched with --enable-logging=stderr --v=1)

Initial ping:
[3985:3985:0403/124536.153928:VERBOSE1:brave_stats_updater.cc(157)] Brave stats ping, url: https://laptop-updates.brave.com/1/usage/brave-core?platform=linux-bc&channel=release&version=0.62.50&daily=true&weekly=true&monthly=true&first=true&woi=2019-04-01&ref=none

"Next Day" ping:

[4259:4259:0404/125741.418387:VERBOSE1:brave_stats_updater.cc(157)] Brave stats ping, url: https://laptop-updates.brave.com/1/usage/brave-core?platform=linux-bc&channel=release&version=0.62.50&daily=true&weekly=false&monthly=false&first=false&woi=2019-04-01&ref=none