Sync: Change Local IDs to GUID based to avoid ID collision

sync/syncable/directory.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 SYNC_SYNCABLE_DIRECTORY_H_
 #define SYNC_SYNCABLE_DIRECTORY_H_
 
 #include <deque>
 #include <set>
 #include <string>
@@ skipping 92 matching lines @@
     // Sync-side transaction version per data type. Monotonically incremented
     // when updating native model. A copy is also saved in native model.
     // Later out-of-sync models can be detected and fixed by comparing
     // transaction versions of sync model and native model.
     // TODO(hatiaol): implement detection and fixing of out-of-sync models.
     //                Bug 154858.
     int64 transaction_version[MODEL_TYPE_COUNT];
     // The store birthday we were given by the server. Contents are opaque to
     // the client.
     std::string store_birthday;
-    // The next local ID that has not been used with this cache-GUID.
-    int64 next_id;
     // The serialized bag of chips we were given by the server. Contents are
     // opaque to the client. This is the serialization of a message of type
     // ChipBag defined in sync.proto. It can contains NULL characters.
     std::string bag_of_chips;
     // The per-datatype context.
     sync_pb::DataTypeContext datatype_context[MODEL_TYPE_COUNT];
   };
 
   // What the Directory needs on initialization to create itself and its Kernel.
   // Filled by DirectoryBackingStore::Load.
@@ skipping 137 matching lines @@
   // Does not take ownership of |delegate|, which must not be NULL.
   // Starts sending events to |delegate| if the returned result is
   // OPENED.  Note that events to |delegate| may be sent from *any*
   // thread.  |transaction_observer| must be initialized.
   DirOpenResult Open(const std::string& name,
                      DirectoryChangeDelegate* delegate,
                      const WeakHandle<TransactionObserver>&
                          transaction_observer);
 
   int64 NextMetahandle();
   // Returns a negative integer unique to this client.

[maniscalco, 2015/05/14 15:54:20]

This comment is now out of date.

[stanisc, 2015/05/14 21:21:55]

Done.

   syncable::Id NextId();
 
   bool good() const { return NULL != kernel_; }
 
   // The download progress is an opaque token provided by the sync server
   // to indicate the continuation state of the next GetUpdates operation.
   void GetDownloadProgress(
       ModelType type,
       sync_pb::DataTypeProgressMarker* value_out) const;
   void GetDownloadProgressAsString(
@@ skipping 377 matching lines @@
 
   base::WeakPtrFactory<Directory> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Directory);
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif // SYNC_SYNCABLE_DIRECTORY_H_