UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36

Steps to reproduce the problem:
1. Start chrome headless shell with --user-data-dir set to a proper directory
2. Create a new browser context and a target inside the context. 
3. Everything looks good
4. Create another new browser context and a target inside the context
5. Now chrome headless shell starts throwing a lot of errors saying the user data directory is already locked

What is the expected behavior?
chrome headless shell should properly store the user data information for multiple contexts and it should be available for reloading the contexts if browser cashes.

What went wrong?
rome_1   | CHROME STDERR >>  [0903/041820.752267:ERROR:service_worker_storage.cc(1465)] Failed to open the serviceworker diskcache: net::ERR_ABORTED
chrome_1   | CHROME STDERR >>  [0903/041820.756881:INFO:CONSOLE(0)] "Uncaught (in promise) AbortError: Failed to register a ServiceWorker: Operation has been aborted", source: https://web.whatsapp.com/ (0)
chrome_1   | CHROME STDERR >>  [0903/041826.458966:ERROR:leveldb_database.cc(319)] Failed to open LevelDB database from /opt/container/chrome-user-data/IndexedDB/https_web.whatsapp.com_0.indexeddb.leveldb,IO error: /opt/container/chrome-user-data/IndexedDB/https_web.whatsapp.com_0.indexeddb.leveldb/LOCK: Lock file already locked. (ChromeMethodOnly: 15::LockFile)

Did this work before? No 

Chrome version: 62.0.3200.0  Channel: stable
OS Version: Ubuntu jessie
Flash Version: 

http://localhost:9222/json/version

{
Browser: "HeadlessChrome/62.0.3200.0",
Protocol-Version: "1.2",
User-Agent: "'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.78 Safari/537.36'",
V8-Version: "6.2.396",
WebKit-Version: "537.36 (@2044a85df703188ab8183a6f8f0fa7970dbf0cb9)",
webSocketDebuggerUrl: "ws://localhost:9222/devtools/browser/999b266e-a943-4c2e-8f15-bcbd9f4e114b"
}

http://localhost:9222/json

[
{
description: "",
devtoolsFrontendUrl: "/devtools/inspector.html?ws=localhost:9222/devtools/page/ed2595bb-2a3f-4d31-8aab-ba0556909083",
id: "ed2595bb-2a3f-4d31-8aab-ba0556909083",
title: "WhatsApp",
type: "page",
url: "https://web.whatsapp.com/",
webSocketDebuggerUrl: "ws://localhost:9222/devtools/page/ed2595bb-2a3f-4d31-8aab-ba0556909083"
},
{
description: "",
devtoolsFrontendUrl: "/devtools/inspector.html?ws=localhost:9222/devtools/page/480e2517-ef64-45b9-84d9-f9159878b7a8",
id: "480e2517-ef64-45b9-84d9-f9159878b7a8",
title: "WhatsApp",
type: "page",
url: "https://web.whatsapp.com/",
webSocketDebuggerUrl: "ws://localhost:9222/devtools/page/480e2517-ef64-45b9-84d9-f9159878b7a8"
},
{
description: "",
devtoolsFrontendUrl: "/devtools/inspector.html?ws=localhost:9222/devtools/page/6db93334-692b-4ba0-94b4-b2eca39ea030",
id: "6db93334-692b-4ba0-94b4-b2eca39ea030",
title: "about:blank",
type: "page",
url: "about:blank",
webSocketDebuggerUrl: "ws://localhost:9222/devtools/page/6db93334-692b-4ba0-94b4-b2eca39ea030"
}
]