We have macOS content process sandboxing tests (in security/sandbox/test and in security/sandbox/common/test/SandboxTestingChildTests.h), but no sandboxing tests for other process types.

Add the WindowServer test and process launch tests to each Mac child process type.

Backed out for causing build bustages on SandboxTestingChildTests.h

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=49a22cd6d6ee1554989514b22da0388bdf78abd7&selectedTaskRun=T8O0l5UiQ_i5jxe98BHTOQ.0

Failure log: https://treeherder.mozilla.org/logviewer?job_id=371065035&repo=autoland

Backout link: https://hg.mozilla.org/integration/autoland/rev/0f85ffd4fbfd3ca1e9a02b86f8433bffb98271ac

[task 2022-03-15T06:01:04.161Z] 06:01:04     INFO -  gmake[4]: Entering directory '/builds/worker/workspace/obj-build/toolkit/components/remote'
[task 2022-03-15T06:01:04.162Z] 06:01:04     INFO -  toolkit/components/remote/nsDBusRemoteClient.o
[task 2022-03-15T06:01:04.162Z] 06:01:04     INFO -  gmake[4]: Leaving directory '/builds/worker/workspace/obj-build/toolkit/components/remote'
[task 2022-03-15T06:01:04.162Z] 06:01:04     INFO -  gmake[4]: Entering directory '/builds/worker/workspace/obj-build/security/sandbox/common'
[task 2022-03-15T06:01:04.165Z] 06:01:04     INFO -  /builds/worker/fetches/sccache/sccache /builds/worker/fetches/clang/bin/clang++ --sysroot /builds/worker/fetches/sysroot-x86_64-linux-gnu -std=gnu++17 -o Unified_cpp_sandbox_common0.o -c  -I/builds/worker/workspace/obj-build/dist/stl_wrappers -I/builds/worker/workspace/obj-build/dist/system_wrappers -include /builds/worker/checkouts/gecko/config/gcc_hidden.h -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fstack-protector-strong -fstack-clash-protection -ftrivial-auto-var-init=pattern -DDEBUG=1 -DOS_POSIX=1 -DOS_LINUX=1 -DMOZ_HAS_MOZGLUE -DMOZILLA_INTERNAL_API -DIMPL_LIBXUL -DSTATIC_EXPORTABLE_JS_API -I/builds/worker/checkouts/gecko/security/sandbox/common -I/builds/worker/workspace/obj-build/security/sandbox/common -I/builds/worker/checkouts/gecko/netwerk/base -I/builds/worker/workspace/obj-build/ipc/ipdl/_ipdlheaders -I/builds/worker/checkouts/gecko/ipc/chromium/src -I/builds/worker/workspace/obj-build/dist/include -I/builds/worker/workspace/obj-build/dist/include/nspr -I/builds/worker/workspace/obj-build/dist/include/nss -DMOZILLA_CLIENT -include /builds/worker/workspace/obj-build/mozilla-config.h -Qunused-arguments -Qunused-arguments -Wall -Wbitfield-enum-conversion -Wdeprecated-this-capture -Wempty-body -Wformat-type-confusion -Wignored-qualifiers -Wpointer-arith -Wshadow-field-in-constructor-modified -Wsign-compare -Wtype-limits -Wno-error=tautological-type-limit-compare -Wunreachable-code -Wunreachable-code-return -Wunused-but-set-parameter -Wno-invalid-offsetof -Wclass-varargs -Wempty-init-stmt -Wfloat-overflow-conversion -Wfloat-zero-conversion -Wloop-analysis -Wno-range-loop-analysis -Wc++2a-compat -Wcomma -Wenum-compare-conditional -Wimplicit-fallthrough -Werror=non-literal-null-conversion -Wstring-conversion -Wno-inline-new-delete -Wno-error=deprecated-declarations -Wno-error=array-bounds -Wno-error=backend-plugin -Wno-error=free-nonheap-object -Wno-error=return-std-move -Wno-error=atomic-alignment -Wno-error=deprecated-copy -Wformat -Wformat-security -Wno-gnu-zero-variadic-macro-arguments -Wno-psabi -Wno-unknown-warning-option -D_GLIBCXX_USE_CXX11_ABI=0 -fno-sized-deallocation -fno-aligned-new -fcrash-diagnostics-dir=/builds/worker/artifacts -fno-exceptions -fPIC -fno-rtti -ffunction-sections -fdata-sections -fno-exceptions -fno-math-errno -pthread -pipe -gdwarf-4 -Xclang -load -Xclang /builds/worker/workspace/obj-build/build/clang-plugin/libclang-plugin.so -Xclang -add-plugin -Xclang moz-check -Os -fno-omit-frame-pointer -funwind-tables -Werror -fno-strict-aliasing  -MD -MP -MF .deps/Unified_cpp_sandbox_common0.o.pp   Unified_cpp_sandbox_common0.cpp
[task 2022-03-15T06:01:04.165Z] 06:01:04     INFO -  In file included from Unified_cpp_sandbox_common0.cpp:20:
[task 2022-03-15T06:01:04.166Z] 06:01:04     INFO -  In file included from /builds/worker/checkouts/gecko/security/sandbox/common/test/SandboxTestingChild.cpp:8:
[task 2022-03-15T06:01:04.166Z] 06:01:04    ERROR -  /builds/worker/checkouts/gecko/security/sandbox/common/test/SandboxTestingChildTests.h:172:12: error: use of undeclared identifier 'posix_spawnp'
[task 2022-03-15T06:01:04.166Z] 06:01:04     INFO -    int rv = posix_spawnp(NULL, "/bin/bash", NULL, NULL, argv, NULL);
[task 2022-03-15T06:01:04.166Z] 06:01:04     INFO -             ^
[task 2022-03-15T06:01:04.166Z] 06:01:04    ERROR -  /builds/worker/checkouts/gecko/security/sandbox/common/test/SandboxTestingChildTests.h:187:7: error: use of undeclared identifier 'nsCocoaFeatures'
[task 2022-03-15T06:01:04.167Z] 06:01:04     INFO -    if (nsCocoaFeatures::OnCatalinaOrLater()) {
[task 2022-03-15T06:01:04.167Z] 06:01:04     INFO -        ^
[task 2022-03-15T06:01:04.167Z] 06:01:04    ERROR -  /builds/worker/checkouts/gecko/security/sandbox/common/test/SandboxTestingChildTests.h:192:3: error: unknown type name 'CFStringRef'
[task 2022-03-15T06:01:04.167Z] 06:01:04     INFO -    CFStringRef filePath = ::CFStringCreateWithCString(kCFAllocatorDefault, uri,
[task 2022-03-15T06:01:04.167Z] 06:01:04     INFO -    ^
[task 2022-03-15T06:01:04.167Z] 06:01:04    ERROR -  /builds/worker/checkouts/gecko/security/sandbox/common/test/SandboxTestingChildTests.h:192:28: error: no member named 'CFStringCreateWithCString' in the global namespace
[task 2022-03-15T06:01:04.168Z] 06:01:04     INFO -    CFStringRef filePath = ::CFStringCreateWithCString(kCFAllocatorDefault, uri,
[task 2022-03-15T06:01:04.168Z] 06:01:04     INFO -                           ~~^
[task 2022-03-15T06:01:04.168Z] 06:01:04    ERROR -  /builds/worker/checkouts/gecko/security/sandbox/common/test/SandboxTestingChildTests.h:192:54: error: use of undeclared identifier 'kCFAllocatorDefault'
[task 2022-03-15T06:01:04.168Z] 06:01:04     INFO -    CFStringRef filePath = ::CFStringCreateWithCString(kCFAllocatorDefault, uri,
[task 2022-03-15T06:01:04.168Z] 06:01:04     INFO -                                                       ^
[task 2022-03-15T06:01:04.168Z] 06:01:04    ERROR -  /builds/worker/checkouts/gecko/security/sandbox/common/test/SandboxTestingChildTests.h:193:54: error: use of undeclared identifier 'kCFStringEncodingUTF8'
[task 2022-03-15T06:01:04.168Z] 06:01:04     INFO -                                                       kCFStringEncodingUTF8);
[task 2022-03-15T06:01:04.169Z] 06:01:04     INFO -                                                       ^
[task 2022-03-15T06:01:04.169Z] 06:01:04    ERROR -  /builds/worker/checkouts/gecko/security/sandbox/common/test/SandboxTestingChildTests.h:194:3: error: unknown type name 'CFURLRef'
[task 2022-03-15T06:01:04.169Z] 06:01:04     INFO -    CFURLRef urlRef = ::CFURLCreateWithFileSystemPath(

https://hg.mozilla.org/mozilla-central/rev/d67e83068906