Return one U+fffd for longest subpart of incomplete utf-8 character.

Return one U+fffd for longest subpart of incomplete utf-8 character.

This brings the utf-8 decoder in line w/ the Unicode spec
recommendation, and also with the utf-8 decoder in V8. This
latter bit is the motivation for this change, since either this
or the v8 utf-8 decoder gets used for JavaScript source code, and
they should agree with each other.

More details + spec references in the bug.

BUG=chromium:662822
Review-Url: https://codereview.chromium.org/2498653002
Cr-Commit-Position: refs/heads/master@{#432470}
(cherry picked from commit 9a8c03cf61f42e45e4c4d2362d97cc2c5abbdc1f)

Committed: https://chromium.googlesource.com/chromium/src/+/cc60468fe8bd421e7e41914992d877a2a1398991

[vogelheim, 2016-11-22 11:00:39]

Description was changed from

==========
Return one U+fffd for longest subpart of incomplete utf-8 character.

This brings the utf-8 decoder in line w/ the Unicode spec
recommendation, and also with the utf-8 decoder in V8. This
latter bit is the motivation for this change, since either this
or the v8 utf-8 decoder gets used for JavaScript source code, and
they should agree with each other.

More details + spec references in the bug.

BUG=chromium:662822

Review-Url: https://codereview.chromium.org/2498653002
Cr-Commit-Position: refs/heads/master@{#432470}
(cherry picked from commit 9a8c03cf61f42e45e4c4d2362d97cc2c5abbdc1f)
==========

to

==========
Return one U+fffd for longest subpart of incomplete utf-8 character.

This brings the utf-8 decoder in line w/ the Unicode spec
recommendation, and also with the utf-8 decoder in V8. This
latter bit is the motivation for this change, since either this
or the v8 utf-8 decoder gets used for JavaScript source code, and
they should agree with each other.

More details + spec references in the bug.

BUG=chromium:662822

Review-Url: https://codereview.chromium.org/2498653002
Cr-Commit-Position: refs/heads/master@{#432470}
(cherry picked from commit 9a8c03cf61f42e45e4c4d2362d97cc2c5abbdc1f)

Committed:
https://chromium.googlesource.com/chromium/src/+/cc60468fe8bd421e7e41914992d8...
==========

[vogelheim, 2016-11-22 11:00:40]

Committed patchset #1 (id:1) manually as
cc60468fe8bd421e7e41914992d877a2a1398991.