Bug 1493549 - Enable media.navigator.streams.fake in WPT r=jgraham

Reland of https://phabricator.services.mozilla.com/D6579 with updated expectations

Differential Revision: https://phabricator.services.mozilla.com/D6676

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

testing/profiles/web-platform/user.js

@@ -10,6 +10,8 @@ user_pref("extensions.autoDisableScopes", 10);
 user_pref("extensions.update.notifyUser", false);
 // Enable test mode to run multiple tests in parallel
 user_pref("focusmanager.testmode", true);
+// Enable fake media streams for getUserMedia
+user_pref("media.navigator.streams.fake", true);
 // Enable pre-fetching of resources
 user_pref("network.preload", true);
 // Enable direct connection

testing/web-platform/meta/mediacapture-image/ImageCapture-creation.https.html.ini

@@ -1,14 +1,10 @@
 [ImageCapture-creation.https.html]
-  expected:
-    if os == "mac": OK
-    TIMEOUT
+  expected: OK
   [grabFrame() of a disabled Track]
     expected: FAIL
 
   [verifies that an ImageCapture cannot be created out of an Audio Track]
-    expected:
-      if os == "mac": FAIL
-      TIMEOUT
+    expected: FAIL
 
   [grabFrame() of an ended Track]
     expected: FAIL