Reland: cros: Replace shelf STATUS_ACTIVE with STATUS_RUNNING

This was reverted due to failures in mash_browser_tests for
ShelfBrowserTest.StatusBubble. The problem was actually
due to 9716183168af9fd41917aca3ce613b9801b670c3 and that CL has been
reverted.

    > cros: Replace shelf STATUS_ACTIVE with STATUS_RUNNING
    >
    > Before the material design shelf we used to show light bars underneath
    > the shelf icons for running apps. An app with an active window had a
    > brighter bar. With the MD redesign we show dots and there is no
    > difference between running and active. Tracking the active state
    > complicates the go/mustash refactor, especially in tests.
    >
    > * Eliminate the active state, which simplifies both code and tests
    > * Remove ShelfButton::STATE_ACTIVE and STATE_FOCUSED, neither of
    >   which are used anymore
    > * Eliminate browser tests that existed mostly to track the active
    >   state
    >
    > Bug: 678687
    > Test: ash_unittests, browser_tests
    > Change-Id: I3dc1b045d44ea1ecc5a311afa4d877d0e908e35a
    > Reviewed-on: https://chromium-review.googlesource.com/757169
    > Reviewed-by: Tom Sepez <[email protected]>
    > Reviewed-by: Michael Wasserman <[email protected]>
    > Commit-Queue: James Cook <[email protected]>
    > Cr-Commit-Position: refs/heads/master@{#514623}

    [email protected],[email protected],[email protected]
    Bug: 678687
    Reviewed-on: https://chromium-review.googlesource.com/757937
    Reviewed-by: Scott Violet <[email protected]>
    Commit-Queue: Scott Violet <[email protected]>
    Cr-Commit-Position: refs/heads/master@{#514685}

Change-Id: Ief70c56e406ed27394716ea0752d10530aefb1f5
Reviewed-on: https://chromium-review.googlesource.com/758800
Reviewed-by: James Cook <[email protected]>
Reviewed-by: Michael Wasserman <[email protected]>
Commit-Queue: James Cook <[email protected]>
Cr-Commit-Position: refs/heads/master@{#514872}
19 files changed