Take Accept-Language into account in CJK font fallback for Windows

Take Accept-Language into account in CJK font fallback for Windows

This patch changes the CJK font fallback for Windows when neither the
content (the lang attribute) nor the UI locale can disambiguate the
Unified Han script.

The first entry in the Accept-Language user preference that can
disambiguate the Han script is taken into account.

BUG=411407

[kojii, 2016-02-12 03:30:57]

Description was changed from

==========
WIP: AL for win

BUG=
==========

to

==========
Take Accept-Language into account in CJK font fallback for Windows

This patch changes the CJK font fallback for Windows when neither the
content (the lang attribute) nor the UI locale can disambiguate the
Unified Han script.

The first entry in the Accept-Language user preference that can
disambiguate the Han script is taken into account.

BUG=411407
==========

[kojii, 2016-02-12 07:04:23]

kojii@chromium.org changed reviewers:
+ drott@chromium.org

[kojii, 2016-02-12 07:04:24]

PTAL.

[drott, 2016-02-12 11:24:03]

I guess this is superceded by https://codereview.chromium.org/1693563003/?

[drott, 2016-02-12 11:25:33]

Sorry, forget my comment, I didn't see the difference Android/Windows.

[kojii, 2016-02-12 17:04:23]

Merging to the Android's CL at https://codereview.chromium.org/1693563003