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

chrome/browser/ui/fast_unload_controller.cc

Index: chrome/browser/ui/fast_unload_controller.cc
diff --git a/chrome/browser/ui/fast_unload_controller.cc b/chrome/browser/ui/fast_unload_controller.cc
index add48b149446e25ca2899372a7c297cc82a0e08f..ca9ab81e41e2b4bd897bc67508e2a5254fae5234 100644
--- a/chrome/browser/ui/fast_unload_controller.cc
+++ b/chrome/browser/ui/fast_unload_controller.cc
@@ -407,8 +407,13 @@ void FastUnloadController::ProcessPendingTabs(bool skip_beforeunload) {
         // we would like devtools to call its own beforeunload handlers first,
         // and then call beforeunload handlers for |contents|.
         // See DevToolsWindow::InterceptPageBeforeUnload for details.
-        if (!DevToolsWindow::InterceptPageBeforeUnload(contents))
-          contents->DispatchBeforeUnload();
+        if (!DevToolsWindow::InterceptPageBeforeUnload(contents)) {
+          if (contents->NeedToFireBeforeUnload()) {
+            contents->DispatchBeforeUnload();
+          } else {
+            ProcessPendingTabs(skip_beforeunload);
+          }
+        }
       } else {
         ProcessPendingTabs(skip_beforeunload);
       }