Use private fields in a few more viewer classes

[Snuffleupagus]

These properties were always intended to be private, so let's use modern JS features to actually enforce that.

[Snuffleupagus]

/botio unittest

[pdfjsbot]

From: Bot.io (Windows)

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Received

Command cmd_unittest from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.193.163.58:8877/61d1e17e5710699/output.txt

[pdfjsbot]

From: Bot.io (Linux m4)

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Received

Command cmd_unittest from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.241.84.105:8877/58176c3b1d24673/output.txt

[pdfjsbot]

From: Bot.io (Linux m4)

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Success

Full output at http://54.241.84.105:8877/58176c3b1d24673/output.txt

Total script time: 2.36 mins

• Unit Tests: Passed

[calixteman]

LGTM.
Looking at #listeners, I think we should replace such map objects by real Map, just to make clearer the role these kind of objects have.

[pdfjsbot]

From: Bot.io (Windows)

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Success

Full output at http://54.193.163.58:8877/61d1e17e5710699/output.txt

Total script time: 10.30 mins

• Unit Tests: Passed

[Snuffleupagus]

Looking at #listeners, I think we should replace such map objects by real Map, just to make clearer the role these kind of objects have.

I've been thinking about that (more generally), but there's some performance issues with Maps compared to regular Objects. In particular Map.prototype.set() is a lot slower than just assigning to an Object, at least in Firefox, please find some context in master...Snuffleupagus:pdf.js:Dict-Map

[calixteman]

Looking at #listeners, I think we should replace such map objects by real Map, just to make clearer the role these kind of objects have.

I've been thinking about that (more generally), but there's some performance issues with Maps compared to regular Objects. In particular Map.prototype.set() is a lot slower than just assigning to an Object, at least in Firefox, please find some context in master...Snuffleupagus:pdf.js:Dict-Map

I filed a bug about that: https://bugzilla.mozilla.org/show_bug.cgi?id=1799154