Fixing Chrome-branded Tests

This page describes how to fix test failures that only occur in Chrome-branded builds. Note that only Google developers can build Chrome-branded builds.

Chrome-branded builds are built with the GN arg is_chrome_branded set to true. There are some build bots that run the Chrome test suites with Chrome-branded builds, and sometimes tests that pass on the "normal" bots fail on the Chrome-branded bots. Here is an example bot.

Test failures in Chrome-branded builds that don’t occur in Chromium builds are generally caused by one of several things:

• Experiments and features enabled for Canary, but not Stable. This happens because generally experiments and features are enabled for Canary before Stable. If the experiment/feature is known, enable it in the test fixture, e.g 5011326, 5018992.
• GetChannel() on Chrome-branded build is “Stable”, because no channel is set. On Chromium builds, it’s usually “Canary”. ScopedCurrentChannel can be used by the test to force the channel to Canary, even for branded builds, e.g., 5003035. If it’s an experiment or feature that needs to be enabled, it’s preferable to force the experiment or feature on, but sometimes it can be hard to figure out the experiment to enable if it's an unfamiliar area of the code.
• Calls to EXPECT_DEATH with DCHECKs in official, non-debug builds don't work, so they should be guarded by (!defined(OFFICIAL_BUILD) || !defined(NDEBUG)), e.g., 5014301. This is needed because the Chrome-branded bots also set the GN arg is_official_build.
• CHECK failure in ui::ResourceBundle::GetLocalizedStringImpl on Windows builds. This happens when a test uses a string that is not used in Chrome. On Windows Chrome-branded builds, we strip out string resources that aren’t used in Chrome. See crbug.com/1181150. The fix is to disable or not build the test for branded builds.