Better remove HistoryNodes

content/common/page_state_serialization.cc

 // 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.
 
 #include "content/common/page_state_serialization.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/pickle.h"
@@ skipping 177 matching lines @@
 // 15: Removes a bunch of values we defined but never used.
 // 16: Switched from blob urls to blob uuids.
 // 17: Add a target frame id number.
 // 18: Add referrer policy.
 // 19: Remove target frame id, which was a bad idea, and original url string,
 //         which is no longer used.
 // 20: Add pinch viewport scroll offset, the offset of the pinched zoomed
 //     viewport within the unzoomed main frame.
 // 21: Add frame sequence number.
 // 22: Add scroll restoration type.
+// 23: Remove frame sequence number, there are easier ways.
 //
 // NOTE: If the version is -1, then the pickle contains only a URL string.
 // See ReadPageState.
 //
 const int kMinVersion = 11;
-const int kCurrentVersion = 22;
+const int kCurrentVersion = 23;
 
 // A bunch of convenience functions to read/write to SerializeObjects.  The
 // de-serializers assume the input data will be in the correct format and fall
 // back to returning safe defaults when not.
 
 void WriteData(const void* data, int length, SerializeObject* obj) {
   obj->pickle.WriteData(static_cast<const char*>(data), length);
 }
 
 void ReadData(SerializeObject* obj, const void** data, int* length) {
@@ skipping 272 matching lines @@
   WriteString(state.target, obj);
   WriteInteger(state.scroll_offset.x(), obj);
   WriteInteger(state.scroll_offset.y(), obj);
   WriteString(state.referrer, obj);
 
   WriteStringVector(state.document_state, obj);
 
   WriteReal(state.page_scale_factor, obj);
   WriteInteger64(state.item_sequence_number, obj);
   WriteInteger64(state.document_sequence_number, obj);
-  WriteInteger64(state.frame_sequence_number, obj);
   WriteInteger(state.referrer_policy, obj);
   WriteReal(state.pinch_viewport_scroll_offset.x(), obj);
   WriteReal(state.pinch_viewport_scroll_offset.y(), obj);
 
   WriteInteger(state.scroll_restoration_type, obj);
 
   bool has_state_object = !state.state_object.is_null();
   WriteBoolean(has_state_object, obj);
   if (has_state_object)
     WriteString(state.state_object, obj);
@@ skipping 38 matching lines @@
     ReadBoolean(obj);  // Skip obsolete target item flag.
     ReadInteger(obj);  // Skip obsolete visit count field.
   }
   state->referrer = ReadString(obj);
 
   ReadStringVector(obj, &state->document_state);
 
   state->page_scale_factor = ReadReal(obj);
   state->item_sequence_number = ReadInteger64(obj);
   state->document_sequence_number = ReadInteger64(obj);
-  if (obj->version >= 21)
-    state->frame_sequence_number = ReadInteger64(obj);
+  if (obj->version >= 21 && obj->version < 23)
+    ReadInteger64(obj); // Skip obsolete frame sequence number.
 
   if (obj->version >= 17 && obj->version < 19)
     ReadInteger64(obj); // Skip obsolete target frame id number.
 
   if (obj->version >= 18) {
     state->referrer_policy =
         static_cast<blink::WebReferrerPolicy>(ReadInteger(obj));
   }
 
   if (obj->version >= 20) {
@@ skipping 111 matching lines @@
       is_null(true) {
 }
 
 ExplodedHttpBody::~ExplodedHttpBody() {
 }
 
 ExplodedFrameState::ExplodedFrameState()
     : scroll_restoration_type(blink::WebHistoryScrollRestorationAuto),
       item_sequence_number(0),
       document_sequence_number(0),
-      frame_sequence_number(0),
       page_scale_factor(0.0),
       referrer_policy(blink::WebReferrerPolicyDefault) {
 }
 
 ExplodedFrameState::ExplodedFrameState(const ExplodedFrameState& other) {
   assign(other);
 }
 
 ExplodedFrameState::~ExplodedFrameState() {
 }
 
 void ExplodedFrameState::operator=(const ExplodedFrameState& other) {
   if (&other != this)
     assign(other);
 }
 
 void ExplodedFrameState::assign(const ExplodedFrameState& other) {
   url_string = other.url_string;
   referrer = other.referrer;
   target = other.target;
   state_object = other.state_object;
   document_state = other.document_state;
   scroll_restoration_type = other.scroll_restoration_type;
   pinch_viewport_scroll_offset = other.pinch_viewport_scroll_offset;
   scroll_offset = other.scroll_offset;
   item_sequence_number = other.item_sequence_number;
   document_sequence_number = other.document_sequence_number;
-  frame_sequence_number = other.frame_sequence_number;
   page_scale_factor = other.page_scale_factor;
   referrer_policy = other.referrer_policy;
   http_body = other.http_body;
   children = other.children;
 }
 
 ExplodedPageState::ExplodedPageState() {
 }
 
 ExplodedPageState::~ExplodedPageState() {
@@ skipping 24 matching lines @@
     float device_scale_factor,
     ExplodedPageState* exploded) {
   g_device_scale_factor_for_testing = device_scale_factor;
   bool rv = DecodePageState(encoded, exploded);
   g_device_scale_factor_for_testing = 0.0;
   return rv;
 }
 #endif
 
 }  // namespace content