Revert of [Chromecast] Use base::FeatureList to control features.

Revert of [Chromecast] Use base::FeatureList to control features. (patchset #7 id:120001 of https://codereview.chromium.org/2825873002/ )

Reason for revert:
cast_features_browsertest.cc is flaky on our internal CQ bot - it's unclear why this did not manifest on the Chromium trybots. 

I assume that state persisting in the PrefService between tests is causing the flakiness. Reverting this patch until I understand the root cause. 

Original issue's description:
> [Chromecast] Use base::FeatureList to control features.
> 
> In Chromium, Finch-enabled features are controlled through base::FeatureList,
> a class which abstracts the experiment framework and developer overrides
> from client code. Though Chromecast's experiment framework is fundamentally
> different (in that it is server-driven) Cast builds can still make use of
> this class. Introduce some utilities to help.
> 
> At boot-up, the pref store will be queried for experiment configs, which
> were cached to disk on the most recent config fetch from the last boot
> cycle. If a developer overrides these features from the command line,
> that value takes precedence. These features will be used to initialize
> base::FeatureList, which can then be statically queried from any client
> code that depends on //base.
> 
> This patch does not actually introduce or convert any existing features
> to use this framework.
> 
> BUG=714291
> BUG= internal b/35424335
> 
> Review-Url: https://codereview.chromium.org/2825873002
> Cr-Commit-Position: refs/heads/master@{#466507}
> Committed: https://chromium.googlesource.com/chromium/src/+/ef03d2b9a67352094516f4e866373378fb961ee8

TBR=halliwell@chromium.org,maclellant@chromium.org,asvitkine@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=714291
Review-Url: https://codereview.chromium.org/2838813003
Cr-Commit-Position: refs/heads/master@{#467041}
Committed: https://chromium.googlesource.com/chromium/src/+/46cfdeaf9d8e4c78dee471195ad0c1b3a6dcf9e3

[slan, 2017-04-25 16:06:33]

The CQ bit was checked by slan@chromium.org

[slan, 2017-04-25 16:06:33]

Created Revert of [Chromecast] Use base::FeatureList to control features.

[commit-bot: I haz the power, 2017-04-25 16:06:59]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-25 17:55:24]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493136393033330, "parent_rev":
"6444ffe806aa0c99eaee4ebe64c31e9962d140da", "commit_rev":
"46cfdeaf9d8e4c78dee471195ad0c1b3a6dcf9e3"}

[commit-bot: I haz the power, 2017-04-25 17:55:36]

Description was changed from

==========
Revert of [Chromecast] Use base::FeatureList to control features. (patchset #7
id:120001 of https://codereview.chromium.org/2825873002/ )

Reason for revert:
cast_features_browsertest.cc is flaky on our internal CQ bot - it's unclear why
this did not manifest on the Chromium trybots. 

I assume that state persisting in the PrefService between tests is causing the
flakiness. Reverting this patch until I understand the root cause. 

Original issue's description:
> [Chromecast] Use base::FeatureList to control features.
> 
> In Chromium, Finch-enabled features are controlled through base::FeatureList,
> a class which abstracts the experiment framework and developer overrides
> from client code. Though Chromecast's experiment framework is fundamentally
> different (in that it is server-driven) Cast builds can still make use of
> this class. Introduce some utilities to help.
> 
> At boot-up, the pref store will be queried for experiment configs, which
> were cached to disk on the most recent config fetch from the last boot
> cycle. If a developer overrides these features from the command line,
> that value takes precedence. These features will be used to initialize
> base::FeatureList, which can then be statically queried from any client
> code that depends on //base.
> 
> This patch does not actually introduce or convert any existing features
> to use this framework.
> 
> BUG=714291
> BUG= internal b/35424335
> 
> Review-Url: https://codereview.chromium.org/2825873002
> Cr-Commit-Position: refs/heads/master@{#466507}
> Committed:
https://chromium.googlesource.com/chromium/src/+/ef03d2b9a67352094516f4e86637...

TBR=halliwell@chromium.org,maclellant@chromium.org,asvitkine@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=714291
==========

to

==========
Revert of [Chromecast] Use base::FeatureList to control features. (patchset #7
id:120001 of https://codereview.chromium.org/2825873002/ )

Reason for revert:
cast_features_browsertest.cc is flaky on our internal CQ bot - it's unclear why
this did not manifest on the Chromium trybots. 

I assume that state persisting in the PrefService between tests is causing the
flakiness. Reverting this patch until I understand the root cause. 

Original issue's description:
> [Chromecast] Use base::FeatureList to control features.
> 
> In Chromium, Finch-enabled features are controlled through base::FeatureList,
> a class which abstracts the experiment framework and developer overrides
> from client code. Though Chromecast's experiment framework is fundamentally
> different (in that it is server-driven) Cast builds can still make use of
> this class. Introduce some utilities to help.
> 
> At boot-up, the pref store will be queried for experiment configs, which
> were cached to disk on the most recent config fetch from the last boot
> cycle. If a developer overrides these features from the command line,
> that value takes precedence. These features will be used to initialize
> base::FeatureList, which can then be statically queried from any client
> code that depends on //base.
> 
> This patch does not actually introduce or convert any existing features
> to use this framework.
> 
> BUG=714291
> BUG= internal b/35424335
> 
> Review-Url: https://codereview.chromium.org/2825873002
> Cr-Commit-Position: refs/heads/master@{#466507}
> Committed:
https://chromium.googlesource.com/chromium/src/+/ef03d2b9a67352094516f4e86637...

TBR=halliwell@chromium.org,maclellant@chromium.org,asvitkine@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=714291

Review-Url: https://codereview.chromium.org/2838813003
Cr-Commit-Position: refs/heads/master@{#467041}
Committed:
https://chromium.googlesource.com/chromium/src/+/46cfdeaf9d8e4c78dee471195ad0...
==========

[commit-bot: I haz the power, 2017-04-25 17:55:37]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/46cfdeaf9d8e4c78dee471195ad0...