Fix two Chrome Apps browser tests with PlzNavigate.

chrome/browser/policy/policy_browsertest.cc

 // Copyright (c) 2012 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 <stdint.h>
 
 #include <algorithm>
 #include <memory>
 #include <string>
@@ skipping 2532 matching lines @@
       extensions::AppWindowRegistry::Get(browser()->profile()));
   OpenApplication(AppLaunchParams(
       browser()->profile(), extension, extensions::LAUNCH_CONTAINER_NONE,
       WindowOpenDisposition::NEW_WINDOW, extensions::SOURCE_TEST));
   extensions::AppWindow* window = add_window_observer.WaitForAppWindow();
   ASSERT_TRUE(window);
 
   // Verify that the window is not in fullscreen mode.
   EXPECT_FALSE(window->GetBaseWindow()->IsFullscreen());
 
+  // For PlzNavigate case, we have to wait for the navigation to commit since
+  // the JS object registration is delayed (see
+  // AppWindowCreateFunction::RunAsync).
+  content::WaitForLoadStop(window->web_contents());
+
   // Verify that the window cannot be toggled into fullscreen mode via apps
   // APIs.
   EXPECT_TRUE(content::ExecuteScript(
       window->web_contents(),
       "chrome.app.window.current().fullscreen();"));
   EXPECT_FALSE(window->GetBaseWindow()->IsFullscreen());
 
   // Verify that the window cannot be toggled into fullscreen mode from within
   // Chrome (e.g., using keyboard accelerators).
   window->Fullscreen();
@@ skipping 1806 matching lines @@
 
   SetEmptyPolicy();
   // Policy not set.
   CheckSystemTimezoneAutomaticDetectionPolicyUnset();
   EXPECT_TRUE(CheckResolveTimezoneByGeolocation(true, false));
   EXPECT_TRUE(manager->TimeZoneResolverShouldBeRunningForTests());
 }
 #endif  // defined(OS_CHROMEOS)
 
 }  // namespace policy