browser doesn't retry to get signed tokens in all cases

[LaurenWags]

Description

While testing I got a Tokens don't exist response from the server on several profiles. When this occurred, the browser did not retry to get signed tokens again. Because of this, I was not served Ads.

Steps to Reproduce

1. Launch clean profile with --enable-logging=stderr --vmodule=brave_ads=3 --log-level=2
2. Enable Rewards
3. Watch terminal

Actual result:

Rarely, you might encounter below message. Afterwards, the browser does not retry to get signed tokens, so Ads are not served to the user.

[16257:775:1029/100754.876923:INFO:refill_tokens.cc(155)] GetSignedTokens
[16257:775:1029/100754.876933:INFO:refill_tokens.cc(157)] GET /v1/confirmation/token/{payment_id}?nonce={nonce}
[16257:775:1029/100754.876943:INFO:refill_tokens.cc(160)] URL Request:
[16257:775:1029/100754.876955:INFO:refill_tokens.cc(163)]   URL: https://ads-serve.brave.com/v1/confirmation/token/13f3291d-ab07-470b-87b3-9d1d7a1db5a5?nonce=b4ac7b58-f0b8-4074-8a7c-b4c7a7c309d5
[16257:775:1029/100755.041816:INFO:refill_tokens.cc(178)] OnGetSignedTokens
[16257:775:1029/100755.041855:INFO:refill_tokens.cc(180)] URL Request Response:
[16257:775:1029/100755.041867:INFO:refill_tokens.cc(181)]   URL: https://ads-serve.brave.com/v1/confirmation/token/13f3291d-ab07-470b-87b3-9d1d7a1db5a5?nonce=b4ac7b58-f0b8-4074-8a7c-b4c7a7c309d5
[16257:775:1029/100755.041879:INFO:refill_tokens.cc(182)]   Response Status Code: 404
[16257:775:1029/100755.041890:INFO:refill_tokens.cc(183)]   Response: {"error":"Tokens don't exist","statusCode":404}
[16257:775:1029/100755.041901:INFO:refill_tokens.cc(184)]   Headers:
[16257:775:1029/100755.041911:INFO:refill_tokens.cc(186)]     accept-ranges: bytes
[16257:775:1029/100755.041921:INFO:refill_tokens.cc(186)]     access-control-allow-origin: *
[16257:775:1029/100755.041931:INFO:refill_tokens.cc(186)]     connection: keep-alive
[16257:775:1029/100755.041941:INFO:refill_tokens.cc(186)]     content-length: 47
[16257:775:1029/100755.041951:INFO:refill_tokens.cc(186)]     content-type: application/json; charset=utf-8
[16257:775:1029/100755.041962:INFO:refill_tokens.cc(186)]     date: Tue, 29 Oct 2019 14:07:55 GMT
[16257:775:1029/100755.041973:INFO:refill_tokens.cc(186)]     etag: W/"2f-vMmf6VLkjFm9SHdT7UNWnWn7nSs"
[16257:775:1029/100755.041983:INFO:refill_tokens.cc(186)]     via: 1.1 varnish
[16257:775:1029/100755.041994:INFO:refill_tokens.cc(186)]     x-cache: MISS
[16257:775:1029/100755.042004:INFO:refill_tokens.cc(186)]     x-cache-hits: 0
[16257:775:1029/100755.042014:INFO:refill_tokens.cc(186)]     x-powered-by: Express
[16257:775:1029/100755.042024:INFO:refill_tokens.cc(186)]     x-served-by: cache-ewr18132-EWR
[16257:775:1029/100755.042034:ERROR:refill_tokens.cc(190)] Failed to get signed tokens

If you keep watching, there are no retry attempts.

Expected result:

When error above is encountered (as it is a legitimate error), the browser should retry to get signed tokens.

Reproduces how often:

Getting the [16257:775:1029/100755.041890:INFO:refill_tokens.cc(183)] Response: {"error":"Tokens don't exist","statusCode":404} is rare, but once you get the message, it is easy to see that the browser does not retry.

Brave version (brave://version info)

encountered with

Brave	0.72.111 Chromium: 78.0.3904.70 (Official Build) dev (64-bit)
Revision	edb9c9f3de0247fd912a77b7f6cae7447f6d3ad5-refs/branch-heads/3904@{#800}
OS	macOS Version 10.13.6 (Build 17G5019)

Version/Channel Information:

• Can you reproduce this issue with the current release? unsure
• Can you reproduce this issue with the beta channel? unsure
• Can you reproduce this issue with the dev channel? encountered here
• Can you reproduce this issue with the nightly channel? unsure

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? n/a
• Does the issue resolve itself when disabling Brave Rewards? n/a
• Is the issue reproducible on the latest version of Chrome? n/a

Miscellaneous Information:

cc @tmancey @jsecretan @brave/legacy_qa

[btlechowski]

QA/Blocked on #7666

[kjozwiak]

Waiting on @tmancey to add some info re: reproducing the 400 issue with Charles Proxy and ensuring that the retry works as expected.

[kjozwiak]

Due to this being hard to QA and which takes up a lot of time, we're going to check a single platform to make sure it's working after speaking with both @tmancey and @jsecretan.

[kjozwiak]

Verification PASSED on macOS 10.15.3 x64 using the following build:

Brave	1.3.110 Chromium: 80.0.3987.78 (Official Build) (64-bit)
Revision	cb5aa81cb0a3a2c674b93bc7ffb34a86cd3b4802-refs/branch-heads/3987@{#752}
OS	macOS Version 10.15.3 (Build 19D76)

• Verified that the STR outlined via Fixes browser doesn't retry to get signed tokens in all cases brave-core#4106 (comment) worked as expected.