Apologies, the command I ran was:

    .\chrome.exe --headless --remote-debugging-port=9222 --remote-debugging-address=0.0.0.0 --user-data-dir=.\user-data --disable-gpu --enable-logging --v=9  https://chromium.org

(It doesn't work when using the IP (192.168.203.228) of my network interface either, however)

This looks like out of scope for TE, hence adding the respective label for it to  triage further.

Seems to be headless-specific.

Are you sure it's headless specific? If not using the --headless flag, it doesn't work for me either. Does it work for you?

--remote-debugging-address is only supported with --headless, so this is headless-specific.

We'll investigate but as a workaround you can use a public IP address in place of 0.0.0.0.

I'm getting that just from normal browsing (didn't even Ctrl+Shift+J at all):

[1653:1676:0424/124050.071070:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.093164:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.116888:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.134129:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.158063:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.179317:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.198497:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.221485:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.240064:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.274655:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.299639:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser
[1653:1676:0424/124050.318052:ERROR:service_manager.cc(477)] InterfaceProviderSpec prevented connection from: content_utility to: content_browser

Chromium	59.0.3068.0 (Developer Build) (64-bit)
Revision	56f79410ed4c847b056e853b5d0bae0b5e34aac1-refs/heads/master@{#463383}
OS	Linux
JavaScript	V8 5.9.202
Flash	
User Agent	Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3068.0 Safari/537.36
Command Line	/usr/lib/chromium/chromium --disk-cache-dir=/tmp/chromiumcache --disable-sync-preferences --disable-plugins --cipher-suite-blacklist=0x0001,0x0002,0x0004,0x0005,0x0017,0x0018,0xc002,0xc007,0xc00c,0xc011,0xc016,0xff80,0xff81,0xff82,0xff83 --disable-component-extensions-with-background-pages --disable-background-networking --disable-internal-flash --disable-bundled-ppapi-flash --disable-default-apps --ssl-version-min=tls1 --disallow-autofill-sync-credential --disable-device-discovery-notifications --no-pings --disable-media-source --disable-ntp-other-sessions-menu --disable-prefixed-encrypted-media --disable-touch-adjustment --disable-views-rect-based-targeting --disable-webgl --disable-account-consistency --enable-async-dns --enable-deferred-image-decoding --enable-download-resumption --enable-drop-sync-credential --disable-material-design-ntp --disable-new-avatar-menu --disable-new-profile-management --enable-offline-auto-reload-visible-only --disable-offline-auto-reload --enable-offline-load-stale-cache --enable-one-copy --enable-panels --disable-password-generation --enable-permissions-bubbles --disable-extensions-on-chrome-urls --disable-pinch-virtual-viewport --disable-pinch --enable-quic --disable-save-password-bubble --enable-session-crashed-bubble --disable-settings-window --use-simple-cache-backend=off --disable-smooth-scrolling --disable-sync-app-list --disable-sync-synced-notifications --enable-tcp-fastopen --disable-touch-editing --enable-web-based-signin --disable-zero-copy --enable-harfbuzz-rendertext --enable-impl-side-painting --enable-lcd-text --num-raster-threads=4 --disable-origin-chip --disable-overlay-scrollbar --remember-cert-error-decisions=-1 --enable-search-button-in-omnibox-always --disable-spelling-auto-correct --tab-capture-downscale-quality=fast --tab-capture-upscale-quality=fast --touch-events=disabled --wallet-service-use-sandbox=0 --enable-gpu-vsync --show-component-extension-options --disable-hyperlink-auditing --enable-vertical-tabs --disable-audio-support-for-desktop-share --disable-features=NoStatePrefetch --disable-es3-apis --force-gpu-rasterization --ssl-version-min=tls1 --disk-cache-dir=/tmp/chromiumcache --disable-sync-preferences --disable-plugins --cipher-suite-blacklist=0x0001,0x0002,0x0004,0x0005,0x0017,0x0018,0xc002,0xc007,0xc00c,0xc011,0xc016,0xff80,0xff81,0xff82,0xff83 --flag-switches-begin --flag-switches-end

Should I be worried? or patch some code out

First, the error message has nothing to do with the address, at least not directly. It's a byproduct of ongoing mojo work. I'm currently getting a different spurious and benign error message. This is just the price you pay for working with a build straight from head.

Second, I can't reproduce the actual problem. Running headless_shell built from head, I can supply my IP address, 0.0.0.0, or 12.0.0.1 and all connect just fine. Note that this is on Linux; I don't have a Windows machine available to test right now.

I'm closing this. Please reopen with more information if you think there is a real problem I've missed, or if it appears to be OS-specific.