Created test verifying resetting the state object after reloading.

ios/web/navigation/history_state_operations_inttest.mm

 // Copyright 2016 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 "base/memory/ptr_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/ios/wait_util.h"
 #import "ios/web/navigation/navigation_item_impl.h"
@@ skipping 51 matching lines @@
 
     // Load the history state test page.
     state_operations_url_ =
         web::test::HttpServer::MakeUrl(kHistoryStateOperationsTestUrl);
     LoadUrl(state_operations_url());
   }
 
   // The URL of the window.location test page.
   const GURL& state_operations_url() { return state_operations_url_; }
 
+  // Reloads the page and waits for the load to finish.
+  void Reload() {
+    ExecuteBlockAndWaitForLoad(GetLastCommittedItem()->GetURL(), ^{
+      // TODO(crbug.com/677364): Use NavigationManager::Reload() once it no
+      // longer requires a web delegate.
+      web_state()->ExecuteJavaScript(ASCIIToUTF16("window.location.reload()"));
+    });
+  }
+
   // Sets the parameters to use for state operations on the test page.  This
   // function executes a script that populates JavaScript values on the test
   // page.  When the "push-state" or "replace-state" buttons are tapped, these
   // parameters will be passed to their corresponding JavaScript function calls.
   void SetStateParams(const std::string& state_object,
                       const std::string& title,
                       const GURL& url) {
     ASSERT_EQ(state_operations_url(), GetLastCommittedItem()->GetURL());
     std::string url_spec = url.possibly_invalid_spec();
     NSString* set_params_script = [NSString
@@ skipping 193 matching lines @@
     web::NavigationItemImpl* item =
         static_cast<web::NavigationItemImpl*>(GetLastCommittedItem());
     std::string item_state =
         base::SysNSStringToUTF8(item->GetSerializedStateObject());
     return item_state == serialized_state;
   });
   // Verify that the forward navigation was not pruned.
   EXPECT_EQ(GetIndexOfNavigationItem(GetLastCommittedItem()) + 1,
             GetIndexOfNavigationItem(about_blank_item));
 }
+
+// Tests that the state object is reset to the correct value after reloading a
+// page whose state has been replaced.
+TEST_F(HistoryStateOperationsTest, StateReplacementReload) {
+  // Set up the state parameters and tap the replace state button.
+  std::string new_state("STATE OBJECT");
+  std::string empty_title;
+  GURL empty_url;
+  SetStateParams(new_state, empty_title, empty_url);
+  ASSERT_TRUE(web::test::TapWebViewElementWithId(web_state(), kReplaceStateId));
+  // Reload the page and check that the state object is present.
+  Reload();
+  ASSERT_TRUE(IsOnLoadTextVisible());
+  base::test::ios::WaitUntilCondition(^bool {
+    return GetJavaScriptState() == new_state;
+  });
+}