[CI] Enable audio tests in Chrome (emscripten-core#23665)

Step one of a fix for emscripten-core#23131 (the second part in emscripten-core#23695).

Enabled Chrome's `FakeAudioOutputStream` for the CI machines and
bypassed the need for user interaction. The Chrome tests are now enabled
with `@requires_sound_hardware`.

Many attempts at replicating the same functionally were tried with
Firefox (details below) but audio would never run so its
`EMTEST_LACKS_SOUND_HARDWARE` was left unchanged.

.circleci/config.yml

@@ -306,16 +306,18 @@ commands:
       - run:
           name: run tests (<< parameters.title >>)
           environment:
-            EMTEST_LACKS_SOUND_HARDWARE: "1"
             EMTEST_DETECT_TEMPFILE_LEAKS: "0"
             # --no-sandbox because we are running as root and chrome requires
             # this flag for now: https://crbug.com/638180
             CHROME_FLAGS_BASE: "--no-first-run -start-maximized --no-sandbox --use-gl=swiftshader --user-data-dir=/tmp/chrome-emscripten-profile --enable-experimental-web-platform-features"
             CHROME_FLAGS_HEADLESS: "--headless=new --remote-debugging-port=1234"
             CHROME_FLAGS_WASM: "--enable-experimental-webassembly-features --js-flags=\"--experimental-wasm-stack-switching --experimental-wasm-type-reflection\""
             CHROME_FLAGS_NOCACHE: "--disk-cache-dir=/dev/null --disk-cache-size=1 --media-cache-size=1 --disable-application-cache --incognito"
+            # The runners lack sound hardware so fallback to a dummy device (and
+            # bypass the user gesture so audio tests work without interaction)
+            CHROME_FLAGS_AUDIO: " --use-fake-device-for-media-stream --autoplay-policy=no-user-gesture-required"
           command: |
-            export EMTEST_BROWSER="/usr/bin/google-chrome $CHROME_FLAGS_BASE $CHROME_FLAGS_HEADLESS $CHROME_FLAGS_WASM $CHROME_FLAGS_NOCACHE"
+            export EMTEST_BROWSER="/usr/bin/google-chrome $CHROME_FLAGS_BASE $CHROME_FLAGS_HEADLESS $CHROME_FLAGS_WASM $CHROME_FLAGS_NOCACHE $CHROME_FLAGS_AUDIO"
             # There are tests in the browser test suite that using libraries
             # that are not included by "./embuilder build ALL".  For example the
             # PIC version of libSDL which is used by test_sdl2_misc_main_module
@@ -369,6 +371,7 @@ commands:
             #       support in headless mode) resolves
             EMTEST_LACKS_GRAPHICS_HARDWARE: "1"
             EMTEST_LACKS_WEBGPU: "1"
+            # TODO: replicate with FF the same as CHROME_FLAGS_AUDIO
             EMTEST_LACKS_SOUND_HARDWARE: "1"
             # OffscreenCanvas support is not yet done in Firefox.
             EMTEST_LACKS_OFFSCREEN_CANVAS: "1"

test/test_browser.py

@@ -3231,6 +3231,7 @@ def test_sdl2_misc_via_object(self):
     '': (['-sUSE_SDL=2', '-sUSE_SDL_MIXER=2'],),
     'dash_l': (['-lSDL2', '-lSDL2_mixer'],),
   })
+  @no_wasm64('https://github.com/libsdl-org/SDL/pull/12332')
   @requires_sound_hardware
   def test_sdl2_mixer_wav(self, flags):
     shutil.copy(test_file('sounds/the_entertainer.wav'), 'sound.wav')
@@ -3244,6 +3245,7 @@ def test_sdl2_mixer_wav(self, flags):
     # TODO: need to source freepats.cfg and a midi file
     # 'mod': (['mid'],    'MIX_INIT_MID', 'midi.mid'),
   })
+  @no_wasm64('https://github.com/libsdl-org/SDL/pull/12332')
   @requires_sound_hardware
   def test_sdl2_mixer_music(self, formats, flags, music_name):
     shutil.copy(test_file('sounds', music_name), '.')
@@ -5469,9 +5471,8 @@ def test_full_js_library_strict(self):
     'es6': (['-sEXPORT_ES6'],),
     'strict': (['-sSTRICT'],),
   })
+  @requires_sound_hardware
   def test_audio_worklet(self, args):
-    if '-sMEMORY64' in args and is_firefox():
-      self.skipTest('https://github.com/emscripten-core/emscripten/issues/19161')
     self.btest_exit('webaudio/audioworklet.c', args=['-sAUDIO_WORKLET', '-sWASM_WORKERS'] + args)
 
   # Tests that audioworklets and workers can be used at the same time
@@ -5490,6 +5491,7 @@ def test_audio_worklet_post_function(self, args):
     '': ([],),
     'closure': (['--closure', '1', '-Oz'],),
   })
+  @requires_sound_hardware
   def test_audio_worklet_modularize(self, args):
     self.btest_exit('webaudio/audioworklet.c', args=['-sAUDIO_WORKLET', '-sWASM_WORKERS', '-sMODULARIZE=1', '-sEXPORT_NAME=MyModule', '--shell-file', test_file('shell_that_launches_modularize.html')] + args)