Refactor debug_daemon_client.h to use debugd::DevFeatureFlag

Refactor debug_daemon_client.h to use debugd::DevFeatureFlag

debug_daemon_client.h used to define its own duplicate enum.  This cl
unifies it to use the enum defined in debugd.

BUG=444146
TEST=locally on chromebook.

Committed: https://crrev.com/4b5aef62bbbf566031efd57921bf2a5ef5498cef
Cr-Commit-Position: refs/heads/master@{#316607}

[xc, 2015-02-13 20:33:08]

xiaohuic@chromium.org changed reviewers:
+ xiyuan@chromium.org

[xiyuan, 2015-02-13 20:59:04]

lgtm

[xc, 2015-02-13 22:01:44]

xiaohuic@chromium.org changed reviewers:
+ stevenjb@chromium.org

[xc, 2015-02-13 22:01:44]

Need owner's review.

[stevenjb, 2015-02-13 23:39:12]

owner lgtm

[xc, 2015-02-17 17:38:38]

The CQ bit was checked by xiaohuic@chromium.org

[commit-bot: I haz the power, 2015-02-17 17:40:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/925903006/1

[commit-bot: I haz the power, 2015-02-17 18:04:57]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-17 18:05:47]

Patchset 1 (id:??) landed as
https://crrev.com/4b5aef62bbbf566031efd57921bf2a5ef5498cef
Cr-Commit-Position: refs/heads/master@{#316607}