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

content/browser/devtools/protocol/devtools_protocol_browsertest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/base64.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 265 matching lines @@
     return url.ReplaceComponents(remove_port).spec();
   }
 
   // Waits for the expected navigations to occur in any order. If an expected
   // navigation occurs, Page.processNavigation is called with the specified
   // navigation_response to either allow it to proceed or to cancel it.
   void ProcessNavigationsAnyOrder(
       std::vector<ExpectedNavigation> expected_navigations) {
     while (!expected_navigations.empty()) {
       std::unique_ptr<base::DictionaryValue> params =
-          WaitForNotification("Page.navigationRequested");
+          WaitForNotification("Page.navigationRequested", true);
 
       std::string url;
       ASSERT_TRUE(params->GetString("url", &url));
 
       // The url will typically have a random port which we want to remove.
       url = RemovePort(GURL(url));
 
       int navigation_id;
       ASSERT_TRUE(params->GetInteger("navigationId", &navigation_id));
       bool is_in_main_frame;
@@ skipping 1467 matching lines @@
       EXPECT_EQ("polyglottal", value);
       found++;
     } else {
       FAIL();
     }
   }
   EXPECT_EQ(2u, found);
 }
 
 }  // namespace content