Revert of Keep track in the browser of which frames have onunload and onbeforeunload handlers.

ui/views/controls/webview/web_dialog_view.cc

Index: ui/views/controls/webview/web_dialog_view.cc
diff --git a/ui/views/controls/webview/web_dialog_view.cc b/ui/views/controls/webview/web_dialog_view.cc
index bb2871a8596eee16eef7a8889f3e315da15c4ef6..81e1882f67fe0d694f37fa2c30a1c53b60a69f14 100644
--- a/ui/views/controls/webview/web_dialog_view.cc
+++ b/ui/views/controls/webview/web_dialog_view.cc
@@ -110,8 +110,7 @@
     return true;
   }
 
-  if (!is_attempting_close_dialog_ &&
-      web_view_->web_contents()->NeedToFireBeforeUnload()) {
+  if (!is_attempting_close_dialog_) {
     // Fire beforeunload event when user attempts to close the dialog.
     is_attempting_close_dialog_ = true;
     web_view_->web_contents()->DispatchBeforeUnload();