[Sync] SyncEngine refactor part 1: interfaces.

components/sync/driver/sync_service.h

Index: components/sync/driver/sync_service.h
diff --git a/components/sync/driver/sync_service.h b/components/sync/driver/sync_service.h
index 83be47b97ff056be867da2c514968d37b3389480..070e0bef93c466b9df10fa4ae885713900afe025 100644
--- a/components/sync/driver/sync_service.h
+++ b/components/sync/driver/sync_service.h
@@ -200,9 +200,9 @@ class SyncService : public DataTypeEncryptionHandler {
   virtual const GoogleServiceAuthError& GetAuthError() const = 0;
   virtual bool HasUnrecoverableError() const = 0;
 
-  // Returns true if the SyncBackendHost has told us it's ready to accept
-  // changes. This should only be used for sync's internal configuration logic
-  // (such as deciding when to prompt for an encryption passphrase).
+  // Returns true if the SyncEngine has told us it's ready to accept changes.

[skym, 2016/12/02 20:54:55]

SyncEngine actually works great here. Could probably get away with "sync engine"
instead as well if you wanted. Mentioning how SyncService is implemented isn't
precisely the job of this interface, I think.

[maxbogue, 2016/12/02 23:59:27]

Removed the second sentence.

+  // This should only be used for sync's internal configuration logic (such as
+  // deciding when to prompt for an encryption passphrase).
   virtual bool IsBackendInitialized() const = 0;
 
   // Return the active OpenTabsUIDelegate. If open/proxy tabs is not enabled or