Introduce composed tree version of lastEditableVisiblePositionBeforePositionInRoot()

Introduce composed tree version of lastEditableVisiblePositionBeforePositionInRoot()

This patch introduces composed tree version of
|lastEditableVisiblePositionBeforePositionInRoot()| for introducing composed
tree version of |VisibleSelection| class.

This patch is a preparation of making selection to handle granularity for web
component, http://crrev.com/1277863002

BUG=513568
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=201914

[yosin_UTC9, 2015-09-08 08:08:12]

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

[yoichio, 2015-09-08 08:22:07]

lgtm

https://codereview.chromium.org/1306053017/diff/1/Source/core/editing/Editing...
File Source/core/editing/EditingUtilitiesTest.cpp (right):

https://codereview.chromium.org/1306053017/diff/1/Source/core/editing/Editing...
Source/core/editing/EditingUtilitiesTest.cpp:95:
EXPECT_EQ(Position(one->firstChild(), 0),
lastEditableVisiblePositionBeforePositionInRoot(Position(one, 0),
host).deepEquivalent());
(one->firstChild(), 0) is after (one, 0).
Ditto to firstEditableVisiblePositionAfterPositionInRoot case
 : https://codereview.chromium.org/1311543006/
Please add description.

[yosin_UTC9, 2015-09-08 09:04:42]

The CQ bit was checked by yosin@chromium.org

[yosin_UTC9, 2015-09-08 09:04:42]

The patchset sent to the CQ was uploaded after l-g-t-m from yoichio@chromium.org
Link to the patchset: https://codereview.chromium.org/1306053017/#ps20001
(title: "2015-09-08T17:46:08　Add TODO for
lastEditableVisiblePositionBeforePositionInRoot() name")

[commit-bot: I haz the power, 2015-09-08 09:04:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1306053017/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1306053017/20001

[commit-bot: I haz the power, 2015-09-08 09:09:56]

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

[commit-bot: I haz the power, 2015-09-08 09:09:57]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[yosin_UTC9, 2015-09-08 12:35:39]

The CQ bit was checked by yosin@chromium.org

[commit-bot: I haz the power, 2015-09-08 12:35:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1306053017/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1306053017/20001

[yosin_UTC9, 2015-09-08 12:35:52]

The CQ bit was unchecked by yosin@chromium.org

[yosin_UTC9, 2015-09-08 12:42:54]

The CQ bit was checked by yosin@chromium.org

[yosin_UTC9, 2015-09-08 12:42:55]

The patchset sent to the CQ was uploaded after l-g-t-m from yoichio@chromium.org
Link to the patchset: https://codereview.chromium.org/1306053017/#ps40001
(title: "2015-09-08T21:42:35")

[commit-bot: I haz the power, 2015-09-08 12:43:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1306053017/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1306053017/40001

[commit-bot: I haz the power, 2015-09-08 13:42:29]

Committed patchset #3 (id:40001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=201914