Add deprecation warning to requestMediaKeySystemAccess on insecure origins.

LayoutTests/http/tests/security/powerfulFeatureRestrictions/old-powerful-features-on-insecure-origin.html

Index: LayoutTests/http/tests/security/powerfulFeatureRestrictions/old-powerful-features-on-insecure-origin.html
diff --git a/LayoutTests/http/tests/security/powerfulFeatureRestrictions/old-powerful-features-on-insecure-origin.html b/LayoutTests/http/tests/security/powerfulFeatureRestrictions/old-powerful-features-on-insecure-origin.html
index fd0c3cc824eee30c4e4b789190a90d52be27a239..e484c5a5f77f6a5927ae447d478d85e27a7d11d1 100644
--- a/LayoutTests/http/tests/security/powerfulFeatureRestrictions/old-powerful-features-on-insecure-origin.html
+++ b/LayoutTests/http/tests/security/powerfulFeatureRestrictions/old-powerful-features-on-insecure-origin.html
@@ -98,6 +98,10 @@ if (window.location.origin != get_host_info().UNAUTHENTICATED_ORIGIN) {
             this.done();
         }));
     }, 'device orientation');
+    
+    promise_test(function(test) {
+        return navigator.requestMediaKeySystemAccess('org.w3.clearkey', [{}]);
+    }, 'requestMediaKeySystemAccess');
 }
 </script>
 </body>