Offload canvas drawing operations to a worker

[Aditi-1400]

This is a follow-up of: #20053

This change works on top of #20016 to move CanvasGraphics operations to a new/different worker thread, thus offloading the heavy page renders and freeing up the main thread.

Note: The TODO(Aditi) comments need to be resolved to mark this pull request as non-draft

[codecov-commenter]

Codecov Report

❌ Patch coverage is 49.20635% with 608 lines in your changes missing coverage. Please review.
✅ Project coverage is 62.59%. Comparing base (cc680f6) to head (5fb68aa).

Files with missing lines	Patch %	Lines
src/display/api.js	42.41%	395 Missing ⚠️
src/core/evaluator.js	48.91%	118 Missing ⚠️
src/display/object_handler.js	80.64%	30 Missing ⚠️
src/core/worker.js	25.71%	26 Missing ⚠️
src/display/canvas.js	42.22%	26 Missing ⚠️
src/display/optional_content_config.js	25.00%	6 Missing ⚠️
src/display/canvas_factory.js	61.53%	5 Missing ⚠️
src/display/worker_options.js	90.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #20729      +/-   ##
==========================================
- Coverage   62.68%   62.59%   -0.09%     
==========================================
  Files         169      170       +1     
  Lines      120476   121434     +958     
==========================================
+ Hits        75521    76016     +495     
- Misses      44955    45418     +463     

Flag	Coverage Δ
fonttest	7.66% <ø> (?)
unittestcli	62.57% <49.20%> (-0.12%)	⬇️

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[nicolo-ribaudo]

/botio test

[moz-tools-bot]

From: Bot.io (Windows)

---

Received

Command cmd_test from @nicolo-ribaudo received. Current queue size: 0

Live output at: http://54.193.163.58:8877/e0227fb9789b076/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Received

Command cmd_test from @nicolo-ribaudo received. Current queue size: 0

Live output at: http://54.241.84.105:8877/b6e4acc21cb49a8/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Failed

Full output at http://54.241.84.105:8877/b6e4acc21cb49a8/output.txt

Total script time: 46.91 mins

• Unit tests: FAILED
• Integration Tests: FAILED
• Regression tests: FAILED

  different ref/snapshot: 14

Image differences available at: http://54.241.84.105:8877/b6e4acc21cb49a8/reftest-analyzer.html#web=eq.log

[moz-tools-bot]

From: Bot.io (Windows)

---

Failed

Full output at http://54.193.163.58:8877/e0227fb9789b076/output.txt

Total script time: 90.47 mins

• Unit tests: FAILED
• Integration Tests: FAILED
• Regression tests: FAILED

  different ref/snapshot: 13

Image differences available at: http://54.193.163.58:8877/e0227fb9789b076/reftest-analyzer.html#web=eq.log

[nicolo-ribaudo]

I was looking through the reftest failures, it seems like the only real ones (the others are minor pixel differences due to the different rendering pipeline, but not visible to humans) are:

• issue8092
• issue16127 (for the gradients inside the font)
• ShowText-ShadingPattern (probably same problem as issue8092)
• issue1133 (page 4, in the huawei logo)
• issue19022

[Aditi-1400]

I was looking through the reftest failures, it seems like the only real ones (the others are minor pixel differences due to the different rendering pipeline, but not visible to humans) are:

• issue8092
• issue16127 (for the gradients inside the font)
• ShowText-ShadingPattern (probably same problem as issue8092)
• issue1133 (page 4, in the huawei logo)
• issue19022

There's also gradient difference in 17069, also there are differences in 19022, same as issue8092

[nicolo-ribaudo]

/botio test

[moz-tools-bot]

From: Bot.io (Windows)

---

Received

Command cmd_test from @nicolo-ribaudo received. Current queue size: 0

Live output at: http://54.193.163.58:8877/832219967f9b55d/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Received

Command cmd_test from @nicolo-ribaudo received. Current queue size: 0

Live output at: http://54.241.84.105:8877/659eb95d2835e52/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Failed

Full output at http://54.241.84.105:8877/659eb95d2835e52/output.txt

Total script time: 46.69 mins

• Unit tests: Passed
• Integration Tests: FAILED
• Regression tests: FAILED

  different ref/snapshot: 12

Image differences available at: http://54.241.84.105:8877/659eb95d2835e52/reftest-analyzer.html#web=eq.log

[moz-tools-bot]

From: Bot.io (Windows)

---

Failed

Full output at http://54.193.163.58:8877/832219967f9b55d/output.txt

Total script time: 78.06 mins

• Unit tests: Passed
• Integration Tests: Passed
• Regression tests: FAILED

  different ref/snapshot: 12

Image differences available at: http://54.193.163.58:8877/832219967f9b55d/reftest-analyzer.html#web=eq.log