Fix handling of word-spacing and nbsp for complex text

Fix handling of word-spacing and nbsp for complex text

Shange HarfBuzzShaper to not normalize non breaking space and update the
logic in adjustSpacing to correctly handle non breaking space characters
during word-space adjustments. The logic for word spacing adjustments is
based on the implementation in SimpleShaper which has been proven right.

R=pdr@chromium.org
BUG=523548
TEST=fast/text/word-spacing-nbsp.html

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=201041

[eae, 2015-08-22 00:11:26]

eae@chromium.org changed reviewers:
+ pdr@chromium.org

[pdr., 2015-08-22 02:29:46]

LGTM

https://codereview.chromium.org/1310803003/diff/1/Source/platform/fonts/shapi...
File Source/platform/fonts/shaping/HarfBuzzShaper.cpp (right):

https://codereview.chromium.org/1310803003/diff/1/Source/platform/fonts/shapi...
Source/platform/fonts/shaping/HarfBuzzShaper.cpp:1175: if (treatAsSpace &&
(currentCharacterIndex || character == noBreakSpaceCharacter) && (character !=
'\t' || !m_textRun.allowTabs()))
This change took me a while to understand, but I'm not sure a comment would even
help :/

[pdr., 2015-08-22 02:29:53]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2015-08-22 02:30:01]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1310803003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1310803003/1

[commit-bot: I haz the power, 2015-08-22 05:20:54]

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

[commit-bot: I haz the power, 2015-08-22 05:20:55]

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

[pdr., 2015-08-22 05:27:32]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2015-08-22 05:27:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1310803003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1310803003/1

[commit-bot: I haz the power, 2015-08-22 10:06:33]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=201041