UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36

Steps to reproduce the problem:
I have never reproduced this, but I have logs from a user of my debugger showing Chrome sending invalid JSON over the debugging websocket.
Reference - https://github.com/Microsoft/vscode-chrome-debug/issues/274#issuecomment-257649589

What is the expected behavior?

What went wrong?
He saw a message like this: 
`{"method":"Runtime.consoleAPICalled","params":{"type":"log","args":[{"type":"string","value":"registerClassNative, class VOTest, persistent name, persistent age, persistent libShort, persistent libLong dtype.checkGlobal: name there is a gap in id list before this (1)"}],"executionContextId":1,"timestamp":1478022231980,036133,"stackTrace":{"callFrames":[{"functionName":"registerClassNative","scriptId":"63","url":"http://localhost:3000/build/ads/mdb/core/dict.js","lineNumber":296,"columnNumber":24},{"functionName":"","scriptId":"54","url":"http://localhost:3000/build/ads/mdb/core/vo.js","lineNumber":33,"columnNumber":45},{"functionName":"e._invokeFactory","scriptId":"37","url":"http://localhost:3000/node_modules/monaco-editor/min/vs/loader.js","lineNumber":6,"columnNumber":13898},{"functionName":"e._complete","scriptId":"37","url":"http://localhost:3000/node_modules/monaco-editor/min/vs/loader.js","lineNumber":6,"columnNumber":14137},{"functionName":"e.resolveDependency","scriptId":"37","url":"htt [...]`

Where 'timestamp' has a comma instead of a decimal point. I don't have repro steps but the version of the affected browser was 54.0.2840.71 (64-bit).

Did this work before? N/A 

Chrome version: 54.0.2840.71  Channel: n/a
OS Version: OS X 10.12.1
Flash Version: Shockwave Flash 23.0 r0