Bug 1483511 - Only build TestAudioDeviceEnumerator.cpp if webrtc is enabled r=dmajor,firefox-build-system-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D3416

--HG--
extra : moz-landing-system : lando

dom/media/gtest/moz.build

@@ -16,7 +16,6 @@ UNIFIED_SOURCES += [
     'MockMediaResource.cpp',
     'TestAudioBuffers.cpp',
     'TestAudioCompactor.cpp',
-    'TestAudioDeviceEnumerator.cpp',
     'TestAudioMixer.cpp',
     'TestAudioPacketizer.cpp',
     'TestAudioSegment.cpp',
@@ -47,6 +46,11 @@ if CONFIG['MOZ_WEBM_ENCODER']:
         'TestWebMWriter.cpp',
     ]
 
+if CONFIG['MOZ_WEBRTC']:
+    UNIFIED_SOURCES += [
+        'TestAudioDeviceEnumerator.cpp',
+    ]
+
 TEST_HARNESS_FILES.gtest += [
     '../test/gizmo-frag.mp4',
     '../test/gizmo.mp4',