PlzNavigate: fix DevToolsProtocolTest.CrossSitePauseInBeforeUnload

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/command_line.h"
 #include "base/json/json_reader.h"
@@ skipping 326 matching lines @@
 IN_PROC_BROWSER_TEST_F(DevToolsProtocolTest, NavigationPreservesMessages) {
   ASSERT_TRUE(embedded_test_server()->Start());
   GURL test_url = embedded_test_server()->GetURL("/devtools/navigation.html");
   NavigateToURLBlockUntilNavigationsComplete(shell(), test_url, 1);
   Attach();
   SendCommand("Page.enable", nullptr, false);
 
   scoped_ptr<base::DictionaryValue> params(new base::DictionaryValue());
   test_url = GetTestUrl("devtools", "navigation.html");
   params->SetString("url", test_url.spec());
+  TestNavigationObserver navigation_observer(shell()->web_contents());
   SendCommand("Page.navigate", std::move(params), true);
+  navigation_observer.Wait();
 
   bool enough_results = result_ids_.size() >= 2u;
   EXPECT_TRUE(enough_results);
   if (enough_results) {
     EXPECT_EQ(1, result_ids_[0]);  // Page.enable
     EXPECT_EQ(2, result_ids_[1]);  // Page.navigate
   }
 
   enough_results = notifications_.size() >= 1u;
   EXPECT_TRUE(enough_results);
@@ skipping 122 matching lines @@
       GURL("javascript:x=1"),
       nullptr,
       gfx::Size());
   WaitForLoadStop(window->web_contents());
   Attach();
   SendCommand("Page.reload", nullptr, false);
   // Should not crash at this point.
 }
 
 }  // namespace content