Rafactoring History is one of the rarely useful feature supported by Eclipse. If you are do lot of changes in the project, using this feature you could see the list of changes done on that project with the brief details about the changes. Note that this is not similar to the local history where local history maintains the version of the file itself which can be replaced with the old versions. Refactoring History provides the hint of all the changes done on the specific project. You can delete the details if you want.
Look at the below screen for updating the Refactoring History settings. If you look at the below picture, it shows the list of changes and time when the change completed. Also “Remove” button will be used for deleting the change history.
Navigate to the path — <Right Click Project> -> Properties -> Refactoring History
Eclipse Tips : Default Browser Settings