Fix for the NavigationControllerTest.BackSubframe test failures with PlzNavigate

content/public/common/page_state.cc

 // Copyright (c) 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 "content/public/common/page_state.h"
 
 #include <stddef.h>
 
 #include "base/files/file_path.h"
 #include "base/strings/nullable_string16.h"
@@ skipping 87 matching lines @@
       state.referenced_files.push_back(base::NullableString16(
           optional_body_file_path->AsUTF16Unsafe(), false));
     }
     state.top.http_body.contains_passwords =
         body_contains_password_data;
   }
 
   return ToPageState(state);
 }
 
+// static
+PageState PageState::CreateForTestingWithSequenceNumbers(
+    const GURL& url,
+    int64_t item_sequence_number,
+    int64_t document_sequence_number) {
+  ExplodedPageState page_state;
+  page_state.top.url_string = ToNullableString16(url.spec());
+  page_state.top.item_sequence_number = item_sequence_number;
+  page_state.top.document_sequence_number = document_sequence_number;
+
+  std::string encoded_page_state;
+  EncodePageState(page_state, &encoded_page_state);
+  return CreateFromEncodedData(encoded_page_state);
+}
+
 PageState::PageState() {
 }
 
 bool PageState::IsValid() const {
   return !data_.empty();
 }
 
 bool PageState::Equals(const PageState& other) const {
   return data_ == other.data_;
 }
@@ skipping 46 matching lines @@
 }
 
 PageState::PageState(const std::string& data)
     : data_(data) {
   // TODO(darin): Enable this DCHECK once tests have been fixed up to not pass
   // bogus encoded data to CreateFromEncodedData.
   //DCHECK(IsValid());
 }
 
 }  // namespace content