Remove more uses of the deprecated EnumSet template class.

Remove more uses of the deprecated EnumSet template class.

EnumtSet has been deprecated for quite some time, and replaced with the
more general and type safe base::Flags template class.

R=jarin@chromium.org

Committed: https://crrev.com/331b87e222e852eb29eb70ff3d6e5942a983c940
Cr-Commit-Position: refs/heads/master@{#29564}

[Benedikt Meurer, 2015-07-10 05:39:17]

Hey Jaro,

Some cleanup. Please take a look.

Thanks,
Benedikt

[Benedikt Meurer, 2015-07-10 06:10:29]

The CQ bit was checked by bmeurer@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-07-10 06:10:42]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1229233002/1

[commit-bot: I haz the power, 2015-07-10 06:23:01]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-10 06:23:02]

Dry run: This issue passed the CQ dry run.

[Jarin, 2015-07-10 08:30:01]

lgtm

[Benedikt Meurer, 2015-07-10 09:33:21]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-07-10 09:33:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1229233002/1

[commit-bot: I haz the power, 2015-07-10 09:35:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-10 09:35:18]

Patchset 1 (id:??) landed as
https://crrev.com/331b87e222e852eb29eb70ff3d6e5942a983c940
Cr-Commit-Position: refs/heads/master@{#29564}