[Sync] Add logic to reassociate tab nodes after restart.

chrome/browser/sync/glue/tab_node_pool.h

Index: chrome/browser/sync/glue/tab_node_pool.h
diff --git a/chrome/browser/sync/glue/tab_node_pool.h b/chrome/browser/sync/glue/tab_node_pool.h
index 8327d061e08551ecf4fb835e39b06b80f1a613f5..15f6a78d45156b6876ff4e901d129207c29e5c0d 100644
--- a/chrome/browser/sync/glue/tab_node_pool.h
+++ b/chrome/browser/sync/glue/tab_node_pool.h
@@ -5,10 +5,12 @@
 #ifndef CHROME_BROWSER_SYNC_GLUE_TAB_NODE_POOL_H_
 #define CHROME_BROWSER_SYNC_GLUE_TAB_NODE_POOL_H_
 
+#include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
 
 class ProfileSyncService;
 
@@ -26,11 +28,11 @@ class TabNodePool {
                                 size_t tab_node_id);
 
   // Add a previously allocated tab sync node to our pool. Increases the size
-  // of tab_syncid_pool_ by one and marks the new tab node as free.
+  // of tab_syncid_pool_ by one and adds node to old tab nodes set..
   // Note: this should only be called when we discover tab sync nodes from
   // previous sessions, not for freeing tab nodes we created through
   // GetFreeTabNode (use FreeTabNode below for that).
-  void AddTabNode(int64 sync_id);
+  void AddOldTabNode(int64 sync_id, size_t tab_node_id);

[Nicolas Zea, 2013/06/06 21:27:39]

I think this should be moved down to be next to the other "old tab" methods

[shashi, 2013/06/11 19:15:06]

Done.

 
   // Returns the sync_id for the next free tab node. If none are available,
   // creates a new tab node.
@@ -54,10 +56,19 @@ class TabNodePool {
   // associated with this machine.
   void FreeTabNode(int64 sync_id);
 
+  // If there is no old node with id |sync_id| return false. Otherwise remove
+  // |sync_id| from old ids pool and return true.
+  bool RemoveIfOldSyncNodeExists(int64 sync_id);
+
+  // Return all the old sync ids that are not in |used_sync_ids| to the free
+  // node pool.
+  void FreeUnusedOldSyncNodes(const std::set<int64>& used_sync_ids);
+
   // Clear tab pool.
   void clear() {
     tab_syncid_pool_.clear();
     tab_pool_fp_ = -1;
+    old_node_syncids_.clear();
   }
 
   // Return the number of tab nodes this client currently has allocated
@@ -77,6 +88,8 @@ class TabNodePool {
   }
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(SyncTabNodePoolTest, TabNodeIdIncreases);
+
   // Pool of all available syncid's for tab's we have created.
   std::vector<int64> tab_syncid_pool_;
 
@@ -86,7 +99,14 @@ class TabNodePool {
   // To get the next free node, use tab_syncid_pool_[tab_pool_fp_--].
   int64 tab_pool_fp_;
 
-  // The machiine tag associated with this tab pool. Used in the title of new
+  // The maximum used tab_node id for a sync node. A new sync node will always
+  // be created with max_used_tab_node_id_ + 1.
+  size_t max_used_tab_node_id_;
+
+  // Set of old sync ids.
+  std::set<int64> old_node_syncids_;
+
+  // The machine tag associated with this tab pool. Used in the title of new
   // sync nodes.
   std::string machine_tag_;