Reland of Change ScopedFeatureList to overrides FeatureList not reset
The current situation is that using ScopedFeatureList resets to an
empty feature list and then enables/disables an explicit list of
features.
That's never what you want for browser tests (or other higher-level
tests) since it effectively overrides higher-level test configurations
(e.g. those in fieldtrial_testing_config.json, or a bot set up to
specifically test a feature).
In this patch:
1. Keep SFL::Init, SFL::InitWithFeatureList,
SFL::InitFromCommandLine reset to empty list but add warning to
remind developer should use them with care.
2. Change SFL::InitAndEnableFeature, SFL::InitAndDisableFeature and
SFL::InitWithFeatures to not reset but override current FeatureList
with given enables/disables.
We also add unit tests for ScopedFeatureList.
BUG=713390
Original-Review-Url: https://codereview.chromium.org/2834583002
Review-Url: https://codereview.chromium.org/2968793002
Cr-Commit-Position: refs/heads/master@{#484921}
CrOS-Libchrome-Original-Commit: e86c74ee8e06e2a7538b273efe5e4f17fc0c38f9
3 files changed