When I run build/android/adb_run_chrome_public, Chrome crashes in WarmupManager.maybePreconnectUrlAndSubResources(WarmupManager.java:232). 

It seems to expect a URL. 

If I pass a URl, Chrome Custom Tabs is opened instead of Chrome.

Previously I could start Chrome with this command. I'm not sure what happened when I pass a URL but I don't think that it should open CCT by default.
(It is documented to start Chrome https://chromium.googlesource.com/chromium/src/+/master/docs/android_build_instructions.md#Running)

Stacktrace:

07-17 14:20:27.474 20556-20556/org.chromium.chrome E/chromium: [ERROR:shell_integration_android.cc(22)] Not implemented reached in shell_integration::DefaultWebClientSetPermission shell_integration::GetDefaultWebClientSetPermission()
07-17 14:20:27.689 20556-20556/org.chromium.chrome E/AndroidRuntime: FATAL EXCEPTION: main
                                                                     Process: org.chromium.chrome, PID: 20556
                                                                     java.lang.NullPointerException: uriString
                                                                         at android.net.Uri$StringUri.<init>(Uri.java:475)
                                                                         at android.net.Uri$StringUri.<init>(Uri.java)
                                                                         at android.net.Uri.parse(Uri.java:437)
                                                                         at org.chromium.chrome.browser.WarmupManager.maybePreconnectUrlAndSubResources(WarmupManager.java:232)
                                                                         at org.chromium.chrome.browser.init.AsyncInitializationActivity.maybePreconnect(AsyncInitializationActivity.java:190)
                                                                         at org.chromium.chrome.browser.init.ChromeBrowserInitializer$5.initFunction(ChromeBrowserInitializer.java:300)
                                                                         at org.chromium.chrome.browser.init.ChromeBrowserInitializer$1NativeInitTask.run(ChromeBrowserInitializer.java:263)
                                                                         at android.os.Handler.handleCallback(Handler.java:751)
                                                                         at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                         at android.os.Looper.loop(Looper.java:154)
                                                                         at android.app.ActivityThread.main(ActivityThread.java:6121)
                                                                         at java.lang.reflect.Method.invoke(Native Method)
                                                                         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889)
                                                                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)