Rewrite TemplateURLService's SyncableService implmentation to avoid sending ACTION_DELETEs to Sync.

chrome/browser/search_engines/template_url_service.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 CHROME_BROWSER_SEARCH_ENGINES_TEMPLATE_URL_SERVICE_H_
 #define CHROME_BROWSER_SEARCH_ENGINES_TEMPLATE_URL_SERVICE_H_
 
 #include <list>
 #include <map>
 #include <set>
@@ skipping 514 matching lines @@
   void ResetTemplateURLGUID(TemplateURL* url, const std::string& guid);
 
   // Attempts to generate a unique keyword for |turl| based on its original
   // keyword. If its keyword is already unique, that is returned. Otherwise, it
   // tries to return the autogenerated keyword if that is unique to the Service,
   // and finally it repeatedly appends special characters to the keyword until
   // it is unique to the Service. If |force| is true, then this will only
   // execute the special character appending functionality.
   string16 UniquifyKeyword(const TemplateURL& turl, bool force);
 
+  // Adds |sync_turl| into the local model, possibly removing or updating a
+  // local TemplateURL to make room for it. This expects |sync_turl| to be a new
+  // entry from Sync, not currently known to the local model. |sync_data| should
+  // be a SyncDataMap where the contents are entries initially known to Sync
+  // during MergeDataAndStartSyncing. Any necessary updates to Sync will be
+  // appended to |change_list|. This can include updates on local TemplateURLs,
+  // if they are already synced. |initial_data| should be a SyncDataMap of the
+  // entries known to the local model during MergeDataAndStartSyncing. If
+  // |sync_turl| replaces a local entry, that entry is removed from
+  // |initial_data| to prevent it from being sent up to Sync.
+  void MergeInSyncTemplateURL(TemplateURL* sync_turl,
+                              SyncDataMap& sync_data,
+                              syncer::SyncChangeList* change_list,
+                              SyncDataMap* initial_data);
+
   // Given a TemplateURL from Sync (cloud) and a local, non-extension
   // TemplateURL with the same keyword, selects "better" and "worse" entries:
   //   * If one of the TemplateURLs is replaceable and the other is not, the
   //     non-replaceable entry is better.
   //   * Otherwise, if |local_turl| was created by policy, is the default
   //     provider, or was modified more recently, it is better.
   //   * Otherwise |sync_turl| is better.
   // Then resolves the conflict:
   //   * If the "worse" entry is |sync_turl|, and it is replaceable, add a
   //     syncer::SyncChange to delete it, and return false.
   //   * If the "worse" entry is |local_turl|, and it is replaceable, remove it
   //     from the service and return true.
   //   * Otherwise, uniquify the keyword of the "worse" entry.  If it is
   //     |local_turl|, update it within the service.  Add a SyncChange to update
   //     things (always for |sync_turl|, sometimes for |local_turl|; see
   //     comments in implementation), and return true.
   // When the function returns true, callers can then go ahead and add or update
   // |sync_turl| within the service.  If it returns false, callers must not add
   // the |sync_turl|, and must Remove() the |sync_turl| if it was being updated.
   // (Be careful; calling Remove() could add an ACTION_DELETE sync change, which
   // this function has already done.  Make sure to avoid duplicates.)
   //
   // Note that we never call this for conflicts with extension keywords because
   // other code (e.g. AddToMaps()) is responsible for correctly prioritizing
   // extension- vs. non-extension-based TemplateURLs with the same keyword.
   bool ResolveSyncKeywordConflict(TemplateURL* sync_turl,
                                   TemplateURL* local_turl,
                                   syncer::SyncChangeList* change_list);
 
+  // Given two synced TemplateURLs with a conflicting keyword, one of which
+  // needs to be added to or updated in the local model (|sync_turl|) and one
+  // which is already known to the local model (|local_turl|), prepares the
+  // local model so that |sync_turl| can be added to it, or applied as an update
+  // to an existing TemplateURL. Since both entries are known to Sync and one of
+  // their keywords will change, an ACTION_UPDATE will be appended to
+  // |change_list| to reflect this change. Note that |local_turl| must not be an
+  // extension keyword.
+  void ResolveSyncKeywordConflict2(TemplateURL* sync_turl,
+                                   TemplateURL* local_turl,
+                                   syncer::SyncChangeList* change_list);
+
   // Returns a TemplateURL from the service that has the same keyword and search
   // URL as |sync_turl|, if it exists.
   TemplateURL* FindDuplicateOfSyncTemplateURL(const TemplateURL& sync_turl);
 
   // Given a TemplateURL from the cloud and a local matching duplicate found by
   // FindDuplicateOfSyncTemplateURL, merges the two. If |sync_turl| is newer,
   // this replaces |local_turl| with |sync_turl| using the service's Remove and
   // Add. If |local_turl| is newer, this replaces |sync_turl| with |local_turl|
   // through through adding appropriate SyncChanges to |change_list|. This
   // method takes ownership of |sync_turl|, and adds it to the model if it is
   // newer, so the caller must release it if need be.
+  // TODO Update document to describe |sync_data|.
   void MergeSyncAndLocalURLDuplicates(TemplateURL* sync_turl,
                                       TemplateURL* local_turl,
+                                      SyncDataMap& sync_data,
                                       syncer::SyncChangeList* change_list);
 
   // Checks a newly added TemplateURL from Sync by its sync_guid and sets it as
   // the default search provider if we were waiting for it.
   void SetDefaultSearchProviderIfNewlySynced(const std::string& guid);
 
   // Retrieve the pending default search provider according to Sync. Returns
   // NULL if there was no pending search provider from Sync.
   TemplateURL* GetPendingSyncedDefaultSearchProvider();
 
@@ skipping 93 matching lines @@
 
   // This is used to log the origin of changes to the default search provider.
   // We set this value to increasingly specific values when we know what is the
   // cause/origin of a default search change.
   DefaultSearchChangeOrigin dsp_change_origin_;
 
   DISALLOW_COPY_AND_ASSIGN(TemplateURLService);
 };
 
 #endif  // CHROME_BROWSER_SEARCH_ENGINES_TEMPLATE_URL_SERVICE_H_