Steps to reproduce the problem:
1. Open chrome://version
2. Check the "Command Line" section.
3. Observe duplicated options. Specifically, --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5

What is the expected behavior?
The keys have the same value for every duplicate so could be shown only once. 

What went wrong?
Duplicates are displayed unnecessarily.

Did this work before? N/A 

Chrome version: 55.0.2883.91  Channel: n/a
OS Version: 7.1.1; Nexus 6P Build/NMF26F
Flash Version: 

Interestingly, the flags appear at the top of the command line list but are then duplicated at the bottom many times. use-mobile-user-agent also appears to be duplicated once but in a different way than the other two. 

Full Command Line output.

Command Line	--use-mobile-user-agent --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --use-mobile-user-agent --enable-pinch --enable-viewport --enable-overlay-scrollbar --validate-input-event-stream --enable-longpress-drag-selection --touch-selection-strategy=direction --disable-gpu-process-crash-limit --main-frame-resizes-are-orientation-changes --disable-composited-antialiasing --ui-prioritize-in-gpu-process --profiler-timing=0 --prerender-from-omnibox=enabled --enable-dom-distiller --flag-switches-begin --reader-mode-heuristics=opengraph --flag-switches-end --enable-instant-extended-api --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5 --top-controls-show-threshold=0.5 --top-controls-hide-threshold=0.5