[sync] Clean up path generation for the local sync database.

components/sync/driver/sync_service_base.h

Index: components/sync/driver/sync_service_base.h
diff --git a/components/sync/driver/sync_service_base.h b/components/sync/driver/sync_service_base.h
index 96a63055a15bd6dc25fca3f2d0787481189b8e63..6df0fd8e6880daccebf2bdceebcd4cf38ad5f9a3 100644
--- a/components/sync/driver/sync_service_base.h
+++ b/components/sync/driver/sync_service_base.h
@@ -40,6 +40,7 @@ class SyncServiceBase : public SyncService, public SyncEngineHost {
                   std::unique_ptr<SigninManagerWrapper> signin,
                   const version_info::Channel& channel,
                   const base::FilePath& base_directory,
+                  const base::FilePath& local_sync_directory,

[Nicolas Zea, 2017/02/21 23:58:40]

I wonder if this would be better plumbed in via the SyncClient, rather than as a
construction param. SyncClient is useful for abstracting away dependencies on
other areas of the code, which seems to fit the local sync logic.

[pastarmovj, 2017/02/22 14:23:14]

Another great idea! :) 

I think this clean up some more the code altogether.

                   const std::string& debug_identifier);
   ~SyncServiceBase() override;
 
@@ -92,6 +93,10 @@ class SyncServiceBase : public SyncService, public SyncEngineHost {
   // Directory files will be selectively targeted instead.
   const base::FilePath sync_data_folder_;
 
+  // The full path to the folder used for storing the local sync database.
+  // It is only used when sync is running against its local backend.
+  const base::FilePath local_sync_directory_;
+
   // An identifier representing this instance for debugging purposes.
   const std::string debug_identifier_;