Make branch in WebFrame::TraceFrame depend on hardcoded values

Change-Id: I378d8444ed8d0526ce1b34983167579e7441aceb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2094313
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748660}

third_party/blink/renderer/core/exported/web_frame.cc

@@ -306,10 +306,11 @@ void WebFrame::TraceFrame(Visitor* visitor, WebFrame* frame) {
   if (!frame)
     return;
 
-  if (auto* web_local_frame = DynamicTo<WebLocalFrameImpl>(frame))
-    visitor->Trace(web_local_frame);
-  else
+  if (frame->IsWebLocalFrame()) {
+    visitor->Trace(To<WebLocalFrameImpl>(frame));
+  } else {
     visitor->Trace(To<WebRemoteFrameImpl>(frame));
+  }
 }
 
 void WebFrame::TraceFrames(Visitor* visitor, WebFrame* frame) {