Get rid of a redundant function Position::deprecatedEditingOffset()

Get rid of a redundant function Position::deprecatedEditingOffset()

This patch gets rid of a |Position::deprecatedEditingOffset()| by replacing
them to |computeEditingOffset()|, since |deprecatedEditingOffset()| is just
calling a |computeEditingOffset()| to simplify code for improving code health.

BUG=513114
TEST=n/a; no behavior changes

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=200779

[yosin_UTC9, 2015-08-18 09:05:22]

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

[yosin_UTC9, 2015-08-18 09:05:22]

PTAL

[hajimehoshi, 2015-08-18 09:12:05]

lgtm

[hajimehoshi, 2015-08-18 09:12:08]

The CQ bit was checked by hajimehoshi@chromium.org

[commit-bot: I haz the power, 2015-08-18 09:12:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1300813002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1300813002/1

[commit-bot: I haz the power, 2015-08-18 13:10:25]

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

[commit-bot: I haz the power, 2015-08-18 13:10:26]

Try jobs failed on following builders:
  win_chromium_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[yosin_UTC9, 2015-08-19 00:45:15]

The CQ bit was checked by yosin@chromium.org

[commit-bot: I haz the power, 2015-08-19 00:45:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1300813002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1300813002/1

[commit-bot: I haz the power, 2015-08-19 01:48:37]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=200779