Remove WebXrPermissionsApi Feature

All code that previously referenced this feature has been removed, as
the feature is now fully enabled. The flag wasn't removed with the code
as I mistakenly believed that there were some finch configs that needed
updating/removing that couldn't be updated/removed until Chrome stable
had the flag enabled by default; however, after re-reading documentation
it seems as though the corresponding finch configs should be left alone.
This thus just removes the feature entry which is no longer doing
anything.

Fixed: 1090108
Change-Id: Iaf3a6121914be83ae72179bc0e89fa60a2d921f1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2308036
Commit-Queue: Alexander Cooper <alcooper@chromium.org>
Commit-Queue: Alex Moshchuk <alexmos@chromium.org>
Auto-Submit: Alexander Cooper <alcooper@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#790132}

content/public/common/content_features.cc

@@ -859,8 +859,6 @@ const base::Feature kWebXrHitTest{"WebXRHitTest",
 // Enables access to experimental WebXR features.
 const base::Feature kWebXrIncubations{"WebXRIncubations",
                                       base::FEATURE_DISABLED_BY_DEFAULT};
-const base::Feature kWebXrPermissionsApi{"WebXrPermissionsApi",
-                                         base::FEATURE_ENABLED_BY_DEFAULT};
 
 #if defined(OS_ANDROID)
 // Autofill Accessibility in Android.

content/public/common/content_features.h

@@ -178,7 +178,6 @@ CONTENT_EXPORT extern const base::Feature kWebXr;
 CONTENT_EXPORT extern const base::Feature kWebXrArModule;
 CONTENT_EXPORT extern const base::Feature kWebXrHitTest;
 CONTENT_EXPORT extern const base::Feature kWebXrIncubations;
-CONTENT_EXPORT extern const base::Feature kWebXrPermissionsApi;
 
 #if defined(OS_ANDROID)
 CONTENT_EXPORT extern const base::Feature kAndroidAutofillAccessibility;