Enable WebXr to use Permissions Prompt

Bug: 1042445
Change-Id: I67e4920f6d0e1d98f51a6392460a8cb9622390eb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2063071
Auto-Submit: Alexander Cooper <alcooper@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#742718}

content/public/common/content_features.cc

@@ -810,7 +810,7 @@ const base::Feature kWebXrHitTest{"WebXRHitTest",
 const base::Feature kWebXrIncubations{"WebXRIncubations",
                                       base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kWebXrPermissionsApi{"WebXrPermissionsApi",
-                                         base::FEATURE_DISABLED_BY_DEFAULT};
+                                         base::FEATURE_ENABLED_BY_DEFAULT};
 
 #if defined(OS_ANDROID)
 // Autofill Accessibility in Android.