Bug 1799435 - Make RFP checks faster. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D161447

dom/canvas/ClientWebGLContext.cpp

@@ -5653,8 +5653,8 @@ void ClientWebGLContext::GetSupportedProfilesASTC(
 
 bool ClientWebGLContext::ShouldResistFingerprinting() const {
   if (mCanvasElement) {
-    // If we're constructed from a canvas element
-    return nsContentUtils::ShouldResistFingerprinting(GetOwnerDoc());
+    // If we're constructed from a canvas element.
+    return mCanvasElement->OwnerDoc()->ShouldResistFingerprinting();
   }
   if (mOffscreenCanvas) {
     // If we're constructed from an offscreen canvas