Fix history navigations in PlzNavigate to use the proper load flags.

content/browser/frame_host/navigation_controller_impl_browsertest.cc

 // Copyright 2014 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 "content/browser/frame_host/navigation_controller_impl.h"
 
 #include <stdint.h>
 #include <algorithm>
 #include <utility>
 #include <vector>
@@ skipping 6797 matching lines @@
 
   // For non-PlzNavigate case, this happens asynchronously.
   if (!IsBrowserSideNavigationEnabled())
     same_tab_observer.Wait();
 
   const NavigationController& controller =
       shell()->web_contents()->GetController();
   ASSERT_EQ(controller.GetPendingEntry(), nullptr);
 }
 
+// Verify that session history navigations (back/forward) correctly hit the
+// cache instead of going to the server. The test loads a page with no-cache
+// header, stops the server, and goes back expecting succesful navigation.

[Charlie Harrison, 2017/03/31 20:12:13]

close but no cigar. s/succesful/successful/

[nasko, 2017/03/31 20:15:53]

Done.

+IN_PROC_BROWSER_TEST_F(NavigationControllerBrowserTest,
+                       HistoryNavigationUsesCache) {
+  GURL no_cache_url(embedded_test_server()->GetURL(
+      "/navigation_controller/page_with_no_cache_header.html"));
+  GURL regular_url(embedded_test_server()->GetURL("/title2.html"));
+
+  NavigationController& controller = shell()->web_contents()->GetController();
+
+  EXPECT_TRUE(NavigateToURL(shell(), no_cache_url));
+  EXPECT_TRUE(NavigateToURL(shell(), regular_url));
+  EXPECT_EQ(2, controller.GetEntryCount());
+
+  EXPECT_TRUE(embedded_test_server()->ShutdownAndWaitUntilComplete());
+
+  TestNavigationObserver back_observer(shell()->web_contents());
+  controller.GoBack();
+  back_observer.Wait();
+
+  EXPECT_TRUE(back_observer.last_navigation_succeeded());
+}
+
 }  // namespace content