PDFJS not installed by default

Description

@GeetaSarvadnya and myself have run into an issue where PDFJS is not being installed for us with clean profiles. I noticed that the last time it appears to have been installed by default was with version 0.54.4. From 0.55.1 onward it is not installed by default for me. (unsure if @GeetaSarvadnya sees the same) I’m using macOS 10.12.6

Steps to Reproduce

1. Use rm -rf ~/Library/Application\ Support/BraveSoftware and rm -rf ~/Library/Caches/BraveSoftware to remove any existing Brave data
2. Delete app from Applications folder and delete existing .dmg file.
3. Download 0.55.1 or later.

Actual result:

PDFJS is not installed by default

Expected result:

PDFJS installed by default

Reproduces how often:

easily

Brave version (chrome://version info)

Brave	0.55.10 Chromium: 70.0.3538.22 (Official Build) beta(64-bit)
Revision	ac9418ba9c3bd7f6baaffa0b055dfe147e0f8364-refs/branch-heads/3538@{#468}
OS	Mac OS X

Reproducible on current release:

• Does it reproduce on brave-browser dev/beta builds? n/a
• Does it reproduce on browser-laptop? n/a

Website problems only:

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

Additional Information

cc @GeetaSarvadnya @srirambv who also experienced the issue however @kjozwiak did not.

[yrliou]

PDF Viewer should be shown without that argument.

[LaurenWags]

Verified passed with

Brave	0.55.13 Chromium: 70.0.3538.54 (Official Build) beta(64-bit)
Revision	4f8e578b6680574714e9ed3bb9f02922b4dde40d-refs/branch-heads/3538@{#937}
OS	Mac OS X

• Verified with https://github.com/brave/brave-browser/issues/1375#issuecomment-428455030
• Verified able to open several PDFs without issue

Verification Passed on

Brave	0.55.13 Chromium: 70.0.3538.54 (Official Build) beta(64-bit)
Revision	4f8e578b6680574714e9ed3bb9f02922b4dde40d-refs/branch-heads/3538@{#937}
OS	Linux

Verification passed on

Brave	0.55.13 Chromium: 70.0.3538.54 (Official Build) beta (64-bit)
Revision	4f8e578b6680574714e9ed3bb9f02922b4dde40d-refs/branch-heads/3538@{#937}
OS	Windows 7