Add a nbsp at the the end of the text when the next text has a leading space.

Add a nbsp at the the end of the text when the next text has a leading space.

This is a regression caused by https://codereview.chromium.org/2175163004.
The above CL adds a plain space between text nodes, but a nbsp should be added
if the next text node has a leading plain space. If not, two spaces are
collapsed into one plain space.

BUG=657631
TEST=editing/inserting/insert-space.html

Review-Url: https://chromiumcodereview.appspot.com/2432083003
Cr-Commit-Position: refs/heads/master@{#426420}
(cherry picked from commit 952d55918cdb455223cabf647cef859486a37b0f)

Committed: https://chromium.googlesource.com/chromium/src/+/9ebff223d5d639167c3efb01a5fa912b3aee05a9

[yosin_UTC9, 2016-11-02 06:30:42]

Description was changed from

==========
Add a nbsp at the the end of the text when the next text has a leading space.

This is a regression caused by https://codereview.chromium.org/2175163004.
The above CL adds a plain space between text nodes, but a nbsp should be added
if the next text node has a leading plain space. If not, two spaces are
collapsed into one plain space.

BUG=657631
TEST=editing/inserting/insert-space.html

Review-Url: https://chromiumcodereview.appspot.com/2432083003
Cr-Commit-Position: refs/heads/master@{#426420}
(cherry picked from commit 952d55918cdb455223cabf647cef859486a37b0f)
==========

to

==========
Add a nbsp at the the end of the text when the next text has a leading space.

This is a regression caused by https://codereview.chromium.org/2175163004.
The above CL adds a plain space between text nodes, but a nbsp should be added
if the next text node has a leading plain space. If not, two spaces are
collapsed into one plain space.

BUG=657631
TEST=editing/inserting/insert-space.html

Review-Url: https://chromiumcodereview.appspot.com/2432083003
Cr-Commit-Position: refs/heads/master@{#426420}
(cherry picked from commit 952d55918cdb455223cabf647cef859486a37b0f)

Committed:
https://chromium.googlesource.com/chromium/src/+/9ebff223d5d639167c3efb01a5fa...
==========

[yosin_UTC9, 2016-11-02 06:30:46]

Committed patchset #1 (id:1) manually as
9ebff223d5d639167c3efb01a5fa912b3aee05a9.