This activity is invoked from another OOTB activity "FreeClipboard" of Data-Portal class.
Parent activity is used for "Clean up pages and properties on the clipboard" and called from unload processing in the desktop to give a chance to remove data that is no longer valid or no longer needed.
As per parent activities description mentioned, it's used for an application specific clean up as mentioned above.
Hope it answers your query, kindly notify if it does by marking this post as answered.
No, I don't think so activity is browser specific. As OOTB, it's available as blank and it allows the developer to write their own logic. You can verify about customisation from History tab of this activity like who has written the logic.