fix: drag region BrowserView calculations on macOS (#29018)

Co-authored-by: Shelley Vohr <[email protected]>

shell/browser/native_browser_view_mac.mm

@@ -349,9 +349,7 @@ void NativeBrowserViewMac::UpdateDraggableRegions(
 
   std::vector<gfx::Rect> drag_exclude_rects;
   if (draggable_regions_.empty()) {
-    const auto bounds = GetBounds();
-    drag_exclude_rects.emplace_back(bounds.x(), bounds.y(), webViewWidth,
-                                    webViewHeight);
+    drag_exclude_rects.emplace_back(0, 0, webViewWidth, webViewHeight);
   } else {
     drag_exclude_rects = CalculateNonDraggableRegions(
         DraggableRegionsToSkRegion(draggable_regions_), webViewWidth,