pdf.js not loading PDF's within the browser

[kjozwiak]

Test Plan

1. Visit https://bitcoin.org/bitcoin.pdf within the URL bar ,PDF should load
2. search for `BTC pdf` within Google and click on the first search result, pdf should be loaded

Description

When loading a PDF directly into the URL, you'll receive a Your file was not found page error and when clicking on an external PDF link, you'll be asked to download the PDF rather than opening it within the browser.

Disabling/Enabling PDF.js from about:preferences#extensions and restarting the browser didn't help either.

Steps to Reproduce

1. load https://bitcoin.org/bitcoin.pdf within the URL bar (PDF not being loaded)
2. search for BTC pdf within Google and click on the first search result (should be the PDF)
3. you'll be asked to download the PDF rather than opening it within the browser

Actual result:

PDF's are not being displayed/loaded within the Brave browser.

Expected result:

PDF's should be loaded within the Brave browser.

Reproduces how often:

100% reproducible when using the above STR.

Brave Version

about:brave info:

Brave: 0.19.101
rev: 30c42b5
Muon: 4.5.18
libchromiumcontent: 63.0.3239.40

Reproducible on current live release:

Nope, looks like a C63 regression.

Additional Information

• macOS 10.12.6 x64 - Reproduced
• Win 10 x64 - Reproduced by @srirambv
• Ununtu 17.10 x64 - Reproduced

[srirambv]

Seems to be fixed on Windows for 0.19.103. PDF loads properly

[diracdeltas]

fixed by brave/muon@fd36d1a

[Corporate-Solutions]

Persistent issue in Android. Just downloaded Brave to tablet two days ago. No PDFs. As if reader is not native.