feat: add webContents.getPrintersAsync()

[RaisinTen]

Description of Change

This deprecates the synchronous and blocking webContents.getPrinters()
function and introduces webContents.getPrintersAsync(), which is
asynchronous and non-blocking.

Signed-off-by: Darshan Sen darshan.sen@postman.com

cc @deepak1556 @nornagon

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• relevant documentation is changed or added
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Deprecates webContents.getPrinters() and introduces webContents.getPrintersAsync()

[deepak1556]

Thanks for working on this, left some additional reviews.

[zcbenz]

It is crashing on Windows:

[7448:1013/065958.767:FATAL:thread_restrictions.cc(104)] Check failed: !*GetBlockingDisallowedTls(). Function marked as blocking was called from a scope that disallows blocking! If this task is running inside the ThreadPool, it needs to have MayBlock() in its TaskTraits. Otherwise, consider making this blocking work asynchronous or, as a last resort, you may use ScopedAllowBlocking (see its documentation for best practices).
46771g_blocking_disallowed 1 set by
46772Backtrace:
46773	base::debug::CollectStackTrace [0x00007FF670C56DE2+18] (o:\base\debug\stack_trace_win.cc:303)
46774	base::debug::StackTrace::StackTrace [0x00007FF670BAE152+18] (o:\base\debug\stack_trace.cc:197)
46775	base::ThreadRestrictions::SetIOAllowed [0x00007FF670C44402+82] (o:\base\threading\thread_restrictions.cc:224)
46776	base::internal::TaskTracker::RunTask [0x00007FF6726036C7+167] (o:\base\task\thread_pool\task_tracker.cc:462)
46777	base::internal::TaskTracker::RunAndPopNextTask [0x00007FF672603401+545] (o:\base\task\thread_pool\task_tracker.cc:433)
46778	base::internal::WorkerThread::RunWorker [0x00007FF6735DF084+964] (o:\base\task\thread_pool\worker_thread.cc:377)
46779	base::internal::WorkerThread::RunPooledWorker [0x00007FF6735DEB98+24] (o:\base\task\thread_pool\worker_thread.cc:267)
46780	base::`anonymous namespace'::ThreadFunc [0x00007FF670C6C88A+266] (o:\base\threading\platform_thread_win.cc:114)
46781	BaseThreadInitThunk [0x00007FF8C9EF7974+20]
46782	RtlUserThreadStart [0x00007FF8CA88A0B1+33]
46783
46784Backtrace:
46785	base::debug::CollectStackTrace [0x00007FF670C56DE2+18] (o:\base\debug\stack_trace_win.cc:303)
46786	base::debug::StackTrace::StackTrace [0x00007FF670BAE152+18] (o:\base\debug\stack_trace.cc:197)
46787	logging::LogMessage::~LogMessage [0x00007FF670BC42EE+190] (o:\base\logging.cc:591)
46788	logging::LogMessage::~LogMessage [0x00007FF670BC5470+16] (o:\base\logging.cc:584)
46789	base::internal::AssertBlockingAllowed [0x00007FF670C4363B+267] (o:\base\threading\thread_restrictions.cc:111)
46790	base::ScopedBlockingCall::ScopedBlockingCall [0x00007FF670C3ED2A+138] (o:\base\threading\scoped_blocking_call.cc:45)
46791	printing::PrintBackendWin::GetDefaultPrinterName [0x00007FF67228A119+169] (o:\printing\backend\print_backend_win.cc:260)
46792	printing::PrintBackendWin::EnumeratePrinters [0x00007FF672289CDE+270] (o:\printing\backend\print_backend_win.cc:242)
46793	base::internal::Invoker<base::internal::BindState<`lambda at ../../electron/shell/browser/api/electron_api_printing.cc:69:33'>,std::__1::vector<printing::PrinterBasicInfo,std::__1::allocator<printing::PrinterBasicInfo> > ()>::RunOnce [0x00007FF66D60056F+111] (o:\base\bind_internal.h:690)
46794	base::OnceCallback<absl::optional<base::FilePath> ()>::Run [0x00007FF66D5D5C51+59] (o:\base\callback.h:100)
46795	base::internal::ReturnAsParamAdapter<std::__1::vector<printing::PrinterBasicInfo,std::__1::allocator<printing::PrinterBasicInfo> > > [0x00007FF66D600975+37] (o:\base\post_task_and_reply_with_result_internal.h:22)
46796	base::internal::Invoker<base::internal::BindState<void (*)(base::OnceCallback<absl::optional<base::FilePath> ()>, std::__1::unique_ptr<absl::optional<base::FilePath>,std::__1::default_delete<absl::optional<base::FilePath> > > *),base::OnceCallback<absl::o [0x00007FF66D5D59A5+53] (o:\base\bind_internal.h:690)
46797	base::`anonymous namespace'::PostTaskAndReplyRelay::RunTaskAndPostReply [0x00007FF67177B2E2+178] (o:\base\threading\post_task_and_reply_impl.cc:100)
46798	base::internal::Invoker<base::internal::BindState<void (*)(base::(anonymous namespace)::PostTaskAndReplyRelay),base::(anonymous namespace)::PostTaskAndReplyRelay>,void ()>::RunOnce [0x00007FF67177B784+84] (o:\base\bind_internal.h:690)
46799	base::TaskAnnotator::RunTask [0x00007FF670C1E0B9+457] (o:\base\task\common\task_annotator.cc:178)
46800	base::internal::TaskTracker::RunSkipOnShutdown [0x00007FF672604287+23] (o:\base\task\thread_pool\task_tracker.cc:664)
46801	base::internal::TaskTracker::RunTask [0x00007FF672603A89+1129] (o:\base\task\thread_pool\task_tracker.cc:528)
46802	base::internal::TaskTracker::RunAndPopNextTask [0x00007FF672603401+545] (o:\base\task\thread_pool\task_tracker.cc:433)
46803	base::internal::WorkerThread::RunWorker [0x00007FF6735DF084+964] (o:\base\task\thread_pool\worker_thread.cc:377)
46804	base::internal::WorkerThread::RunPooledWorker [0x00007FF6735DEB98+24] (o:\base\task\thread_pool\worker_thread.cc:267)
46805	base::`anonymous namespace'::ThreadFunc [0x00007FF670C6C88A+266] (o:\base\threading\platform_thread_win.cc:114)
46806	BaseThreadInitThunk [0x00007FF8C9EF7974+20]
46807	RtlUserThreadStart [0x00007FF8CA88A0B1+33]
46808Task trace:
46809Backtrace:
46810	electron::api::GetPrinterListAsync [0x00007FF66D5FF9F3+227] (o:\electron\shell\browser\api\electron_api_printing.cc:68)
46811	IPC::`anonymous namespace'::ChannelAssociatedGroupController::Accept [0x00007FF670F109AA+1546] (o:\ipc\ipc_mojo_bootstrap.cc:937)
46812	mojo::SimpleWatcher::Context::Notify [0x00007FF670E2A551+347] (o:\mojo\public\cpp\system\simple_watcher.cc:99)
46813IPC message handler context: 0xCA602648
46814Crash keys:
46815  "total-discardable-memory-allocated" = "0"
46816  "osarch" = "x86_64"
46817  "pid" = "7448"
46818  "ptype" = "browser"
46819  "chrome-trace-id" = "17021947898329446379"
46820  "ui_scheduler_async_stack" = "0x7FF66D70E8DF 0x0"
46821  "io_scheduler_async_stack" = "0x7FF66FD9394D 0x7FF66D630CF2"
46822  "platform" = "win32"
46823  "process_type" = "browser"
46824
46825✗ Electron tests failed with code 0x80000003.
46826error Command failed with exit code 1.
46827

[RaisinTen]

@zcbenz the crash has been fixed.

[zcbenz]

API looks good to me.

[jkleinsc]

API LGTM

[jkleinsc]

Merging as CI failure is known flake already resolved.

[release-clerk]

Release Notes Persisted

Deprecates webContents.getPrinters() and introduces webContents.getPrintersAsync()