As per https://issues.chromium.org/issues/425801332 this should be resolved once Chrome 140 is out. Manual test against chrome canary verifies this.

Nice. We might want to setup CI so we can test against beta releases of Chrome (I think Ruby bindings do this). I'm not sure if it would add too much noise... but it would be cool to see breaking changes and fixes in upcoming releases so we can be ready when they hit the stable channel.

We already have http archives for linux_beta_chrome and its driver. I guess they were added when Ruby added chrome beta support.
I am working on adding chrome beta bazel targets for python in CI-RBE.

Currently, the bazel targets look like - //py:common-chrome-test/selenium/webdriver/common/fedcm_tests.py.
I will configure the beta ones to look like - //py:common-chrome-beta-test/selenium/webdriver/common/fedcm_tests.py.

I made some changes, I will open a draft PR to see if it works as intended.

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

@pytest.mark.xfail_safari(reason="FedCM not supported")
@pytest.mark.xfail_firefox(reason="FedCM not supported")
@pytest.mark.xfail_ie(reason="FedCM not supported")
@pytest.mark.xfail_remote(reason="FedCM not supported, since remote uses Firefox")
class TestFedCM:

PR Code Suggestions ✨

Explore these optional code suggestions:

 @pytest.mark.xfail_safari(reason="FedCM not supported")
 @pytest.mark.xfail_firefox(reason="FedCM not supported")
 @pytest.mark.xfail_ie(reason="FedCM not supported")
 @pytest.mark.xfail_remote(reason="FedCM not supported, since remote uses Firefox")
 
+def _ensure_fedcm_available(driver):
+    # Skip if FedCM capability/feature flag is missing
+    caps = getattr(driver, "capabilities", {}) or {}
+    browser_name = (caps.get("browserName") or "").lower()
+    fedcm_supported = caps.get("fedcmSupported") or caps.get("se:fedcmSupported")
+    if browser_name == "chrome" and fedcm_supported is False:
+        pytest.skip("FedCM not enabled in Chrome configuration")
+