Tested with latest Nightly and Beta on Windows 8.1 Breakpoints and watch expressions in the debugger persist, even if set in private windows which got closed and after 'Clear recent history' calls. Steps to reproduce: 1. Open browser. 2. From the 'File' menu, select 'Open New Private Window'. 3. Open https://www.mozilla.org/en-US/ 4. Open the debugger (Ctrl+Shift+S) 5. Select a variable as text with the mouse. 6. Open the context menu and use 'Add watch expression'. 7. Set a breakpoint for a line by clicking left of a line number. 8. Close the private window. 9. Open https://www.mozilla.org/en-US/ in the normal window. 10. Open the debugger (Ctrl+Shift+S) Actual result: Watch expression and breakpoint from the private window shown. Expected result: Neither watch expression nor breakpoint shown. 11. Close the developer tools. 12. From the "History" menu, use "Clear recent history". 13. Run it, even 1h should be sufficient. 14. Open the debugger (Ctrl+Shift+S) Actual result: Watch expression and breakpoint from the private window shown. Expected result: Neither watch expression nor breakpoint shown. Expressions are stored in devtools.debugger.expressions and might identify the site which had been debugged. Breakpoints are stored in devtools.debugger.pending-breakpoints and contain the url of the file for which the breakpoint had been set.