Add GN flag to disable building cloud print and disable pdfium on non-windows

[rht]

This partially addresses #1958 except on Windows.
cc: @fmarier

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Windows
  • macOS
  • Linux
• Verified that these changes pass automated tests (npm test brave_unit_tests && npm test brave_browser_tests) on
  • Windows
  • macOS
  • Linux
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Requested a security/privacy review as needed.

Test Plan:

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions.

[bridiver]

is this just cloud printing? cc @darkdh

[rht]

Whoops, that's all of printing. I found the flag at https://github.com/Eloston/ungoogled-chromium/blob/master/patches/inox-patchset/0005-disable-default-extensions.patch#L19-L23. But it looks like these particular lines need to be removed in order to disable just cloud printing.

[rht]

From the output of brave/brave-core#980 (comment), technically enable_print_preview is technically true for all platforms. So pdfium can't be disabled.

[fmarier]

This latest patch runs into the same assertion failure as before:

ERROR at //printing/BUILD.gn:20:3: Assertion failed.
  assert(enable_pdf,
  ^-----
Windows basic printing or print preview needs pdf: set enable_pdf=true.
See //BUILD.gn:142:7: which caused the file to be included.
      "//printing:printing_unittests",
      ^------------------------------

[rht]

Yeah, it is impossible to disable unless print preview uses pdf.js.

[bsclifton]

Closing as we solved this issue and are now using PDFium

[rht]

#3846