* Disable flaky Chromium test SocketApiTest.SocketTCPExtension
Re-add filter entry for SocketApiTest.SocketTCPExtension that was
lost during a Chromium version update. This is an upstream Chromium
test (chrome/browser/extensions/api/socket/socket_apitest.cc) with a
known flakiness rate of 5.8% in LUCI Analysis (30-day lookback,
83,121 verdicts). Already disabled on Windows by Chromium
(crbug.com/1319604). Brave has no chromium_src overrides in the
socket API path.
The test intermittently fails in testPendingCallback because TCP
read() returns partial data (HTTP headers only) when the response
arrives in multiple segments — the test incorrectly assumes a single
read returns the complete response.
Resolves https://github.com/brave/brave-browser/issues/54922
* Add inline comment for SocketApiTest filter entry
Netzenbot
df69d8be23