C80 - unable to open PDF

[LaurenWags]

Description

Originally reported by @AlexeyBarabash

Unable to open PDFs on chromium 80 versions of Brave.

Steps to Reproduce

1. Have C80 version installed
2. Try to open a PDF such as: https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf

Actual result:

PDF does not display

Expected result:

PDF should display

Reproduces how often:

easily

Brave version (brave://version info)

Brave	1.5.81 Chromium: 80.0.3987.78 (Official Build) nightly (64-bit)
Revision	cb5aa81cb0a3a2c674b93bc7ffb34a86cd3b4802-refs/branch-heads/3987@{#752}
OS	macOS Version 10.14.6 (Build 18G103)

Version/Channel Information:

• Can you reproduce this issue with the current release? no
• Can you reproduce this issue with the beta channel? no
• Can you reproduce this issue with the dev channel? no
• Can you reproduce this issue with the nightly channel? yes

Other Additional Information:

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

Miscellaneous Information:

cc @mkarolin @rebron @brave/legacy_qa

[btlechowski]

Verification passed on

Brave	1.3.111 Chromium: 80.0.3987.85 (Official Build) (64-bit)
Revision	583b05dfa4ffc657f0f7c5cc13f53aa17c9a5bcf-refs/branch-heads/3987@{#791}
OS	Ubuntu 18.04 LTS

Verified test plan from brave/brave-core#4500. Also verified cases from manual testrun.

Verification PASSED on macOS 10.15.3 x64 using the following build:

Brave	1.3.111 Chromium: 80.0.3987.85 (Official Build) (64-bit)
Revision	583b05dfa4ffc657f0f7c5cc13f53aa17c9a5bcf-refs/branch-heads/3987@{#791}
OS	macOS Version 10.15.3 (Build 19D76)

• ensured that opening PDF's from search engine results didn't cause any issues
• ensured that opening local PDF's within Brave didn't cause any issues
• ensured that opening HTTP/HTTPS PDF's didn't cause any issues
  • http://www.pdf995.com/samples/pdf.pdf
  • https://basicattentiontoken.org/BasicAttentionTokenWhitePaper-4.pdf
• ensured restarting Brave while PDF is active loads the PDF without any issues
• ensured that printing within Brave works without any issues
• ensured dynamically generated PDF's are loading without any issues
  • https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.105.6357&rep=rep1&type=pdf

Verification passed on

Brave	1.3.111 Chromium: 80.0.3987.85 (Official Build) (64-bit)
Revision	583b05dfa4ffc657f0f7c5cc13f53aa17c9a5bcf-refs/branch-heads/3987@{#791}
OS	Windows 10 OS Version 1803 (Build 17134.1006)

• ensured that opening PDF's from search engine results didn't cause any issues
• ensured that opening local PDF's within Brave didn't cause any issues
• ensured that opening HTTP/HTTPS PDF's didn't cause any issues
  • http://www.pdf995.com/samples/pdf.pdf
  • https://basicattentiontoken.org/BasicAttentionTokenWhitePaper-4.pdf
• ensured restarting Brave while PDF is active loads the PDF without any issues
• ensured that printing within Brave works without any issues
• ensured dynamically generated PDF's are loading without any issues
  https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.105.6357&rep=rep1&type=pdf

• Logged Follow up of #8044 - C80 - unable to open PDF in PT and TOR tabs #8090
• Verified both clean and upgraded profiles