[Sync] Fix typo in comment

Bug: none
Change-Id: I663dadcd4d34bcc0964b45dcbcc78621b5b213a2
Reviewed-on: https://chromium-review.googlesource.com/565263Reviewed-by: Stanislav Chiknavaryan <stanisc@chromium.org>
Commit-Queue: Stanislav Chiknavaryan <stanisc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#485420}

components/sync/model/attachments/attachment_store.h

@@ -198,7 +198,7 @@ class AttachmentStoreForSync : public AttachmentStore {
                          Component sync_component);
 
   // |sync_component_| is passed to frontend when sync related operations are
-  // perfromed.
+  // performed.
   const Component sync_component_;
 
   DISALLOW_COPY_AND_ASSIGN(AttachmentStoreForSync);