Use EditingTestBase for StyledMarkupSerializerTest

Use EditingTestBase for StyledMarkupSerializerTest

This CL changes StyledMarkupSerializerTest to inherit EditingTestBase
to reduce duplicated code.

BUG=n/a
TEST=n/a; no behavior change

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197795

[hajimehoshi, 2015-06-24 09:10:29]

hajimehoshi@chromium.org changed reviewers:
+ yosin@chromium.org

[hajimehoshi, 2015-06-24 09:10:30]

PTAL

[yosin_UTC9, 2015-06-24 09:27:38]

lgtm

In description, s/redundant/duplicated/ ?

[hajimehoshi, 2015-06-24 09:48:33]

Patchset #2 (id:20001) has been deleted

[hajimehoshi, 2015-06-24 10:15:41]

I found this requires rebasing.

[hajimehoshi, 2015-06-25 02:29:04]

The CQ bit was checked by hajimehoshi@chromium.org

[hajimehoshi, 2015-06-25 02:29:05]

The patchset sent to the CQ was uploaded after l-g-t-m from yosin@chromium.org
Link to the patchset: https://codereview.chromium.org/1204853003/#ps60001
(title: "rebase")

[commit-bot: I haz the power, 2015-06-25 02:29:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1204853003/60001

[commit-bot: I haz the power, 2015-06-25 03:42:42]

Committed patchset #3 (id:60001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197795