Remove unused BasePdfManager/LocalPdfManager methods

[Snuffleupagus]

• Remove the unused LocalPdfManager.prototype.requestRange method

  This method is never invoked, since the LocalPdfManager is only used when all data is already available.
  More specifically, the requestRange method is only called from:

  • pdf.js/src/core/document.js

    Lines 2042 to 2045 in 49ff3dc

    	if (!(ex instanceof MissingDataException)) {
    	throw ex;
    	}
    	await this.pdfManager.requestRange(begin, end);

  • pdf.js/src/core/pdf_manager.js

    Lines 227 to 230 in 49ff3dc

    	if (!(ex instanceof MissingDataException)) {
    	throw ex;
    	}
    	await this.requestRange(ex.begin, ex.end);

  • pdf.js/src/core/xref.js

    Lines 1050 to 1053 in 49ff3dc

    	if (!(ex instanceof MissingDataException)) {
    	throw ex;
    	}
    	await this.pdfManager.requestRange(ex.begin, ex.end);

  Note how in all those cases a MissingDataException must have been thrown in order for that method to be called, and that exception is only ever thrown from the src/core/chunked_stream.js file.
  The classes in that file are only invoked from the NetworkPdfManager constructor, hence we know that LocalPdfManager.prototype.requestRange is indeed unused.

• Remove the unused BasePdfManager.prototype.ensureXRef method (PR 20333 follow-up)

  This method became unused in PR Fix incremental saving with hybrid references #20333, so let's just remove it now.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.12%. Comparing base (49ff3dc) to head (af429da).

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #21827      +/-   ##
==========================================
- Coverage   90.18%   90.12%   -0.07%     
==========================================
  Files         264      264              
  Lines       67312    67310       -2     
==========================================
- Hits        60707    60664      -43     
- Misses       6605     6646      +41     

Flag	Coverage Δ
browsertest	66.30% <ø> (-0.02%)	⬇️
fonttest	8.92% <ø> (ø)
integrationtest	69.32% <ø> (-0.08%)	⬇️
unittest	58.38% <ø> (+<0.01%)	⬆️
unittestcli	56.96% <ø> (+<0.01%)	⬆️

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[Snuffleupagus]

/botio browsertest

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Received

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

Live output at: http://54.241.84.105:8877/8f3d95fa23c9bdc/output.txt

[moz-tools-bot]

From: Bot.io (Windows)

---

Received

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

Live output at: http://54.193.163.58:8877/848179b115830d1/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Success

Full output at http://54.241.84.105:8877/8f3d95fa23c9bdc/output.txt

Total script time: 19.17 mins

• Regression tests: Passed

[moz-tools-bot]

From: Bot.io (Windows)

---

Success

Full output at http://54.193.163.58:8877/848179b115830d1/output.txt

Total script time: 24.00 mins

• Regression tests: Passed

[timvandermeij]

Thank you for cleaning this up!