Version: 52.0.2743.82 and tip of tree (8/4)
OS: Linux, Windows (haven't tried Mac yet)

What steps will reproduce the problem?
(1) Go to Google.com and set a "Node Removed" DOM breakpoint on the main logo image.
(2) Refresh the page.

What is the expected output?
Each unique DOM breakpoint (DOM node + breakpoint type) is only shown once.

What do you see instead?
The same DOM breakpoint is shown twice in the DOM breakpoints sidebar pane.

Extra debugging info:
I can only repro this issue on certain pages. The issue seems to be that WebInspector.domBreakpointsSidebarPane.restoreBreakpoints(domModel) in ElementsPanel.js gets called multiple times from a single refresh and in the different invocations the nodeId is different for the same DOM node.