Add item and document sequence numbers to FrameNavigationEntry.

content/public/common/frame_navigate_params.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_COMMON_FRAME_NAVIGATE_PARAMS_H_
 #define CONTENT_PUBLIC_COMMON_FRAME_NAVIGATE_PARAMS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 15 matching lines @@
   // page IDs for user actions, and the old page IDs will be reloaded when
   // iframes are loaded automatically.
   int32 page_id;
 
   // The unique ID of the NavigationEntry for browser-initiated navigations.
   // This value was given to the render process in the HistoryNavigationParams
   // and is being returned by the renderer without it having any idea what it
   // means. If the navigation was renderer-initiated, this value is 0.
   int nav_entry_id;
 
+  // The item sequence number identifies each stop in the session history.  It
+  // is unique within the renderer process and makes a best effort to be unique
+  // across browser sessions (using a renderer process timestamp).
+  int64 item_sequence_number;
+
+  // The document sequence number is ssed to identify cross-document navigations

[Avi (use Gerrit), 2015/06/18 20:36:07]

s/ssed/used/

+  // in session history.  It increments for each new document and is unique in
+  // the same way as |item_sequence_number|.  In-page navigations get a new item
+  // sequence number but the same document sequence number.
+  int64 document_sequence_number;
+
   // URL of the page being loaded.
   GURL url;
 
   // The base URL for the page's document when the frame was committed. Empty if
   // similar to 'url' above. Note that any base element in the page has not been
   // parsed yet and is therefore not reflected.
   // This is of interest when a MHTML file is loaded, as the base URL has been
   // set to original URL of the site the MHTML represents.
   GURL base_url;
 
@@ skipping 21 matching lines @@
   // Contents MIME type of main frame.
   std::string contents_mime_type;
 
   // Remote address of the socket which fetched this resource.
   net::HostPortPair socket_address;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_FRAME_NAVIGATE_PARAMS_H_