Add a target_frame_id to the history serialization format.

content/common/page_state_serialization.h

 // Copyright 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.
 
 #ifndef CONTENT_COMMON_PAGE_STATE_SERIALIZATION_H_
 #define CONTENT_COMMON_PAGE_STATE_SERIALIZATION_H_
 
 #include <vector>
 
 #include "base/strings/nullable_string16.h"
@@ skipping 32 matching lines @@
 struct CONTENT_EXPORT ExplodedFrameState {
   base::NullableString16 url_string;
   base::NullableString16 original_url_string;
   base::NullableString16 referrer;
   base::NullableString16 target;
   base::NullableString16 state_object;
   std::vector<base::NullableString16> document_state;
   gfx::Point scroll_offset;
   int64 item_sequence_number;
   int64 document_sequence_number;
+  int64 target_frame_id;
   double page_scale_factor;
   ExplodedHttpBody http_body;
   std::vector<ExplodedFrameState> children;
 
   ExplodedFrameState();
   ~ExplodedFrameState();
 };
 
 struct CONTENT_EXPORT ExplodedPageState {
   std::vector<base::NullableString16> referenced_files;
@@ skipping 11 matching lines @@
 #if defined(OS_ANDROID)
 CONTENT_EXPORT bool DecodePageStateWithDeviceScaleFactorForTesting(
     const std::string& encoded,
     float device_scale_factor,
     ExplodedPageState* exploded);
 #endif
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_PAGE_STATE_SERIALIZATION_H_