Change kerning & ligature tests

Change kerning & ligature tests

Change the font kerning and ligature tests to be pixel tests instead of
ref-tests as the current references are built on the assumption that no
font features are enabled for text by default. In many ways these tests
do not currently test our kerning & ligature features instead they test
the difference between the simple and complex paths.

Changing these to be pixel tests allows the tests to correctly test the
rendering of these font features.

BUG=536784
R=drott@chromium.org

Committed: https://crrev.com/80b1511e005db3babec3ed84c23afbfda2513ee2
Cr-Commit-Position: refs/heads/master@{#353492}

[eae, 2015-10-12 07:58:30]

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

[drott, 2015-10-12 08:16:15]

LGTM 😢

[eae, 2015-10-12 08:18:13]

Patchset #1 (id:1) has been deleted

[eae, 2015-10-12 08:20:17]

The CQ bit was checked by eae@chromium.org

[eae, 2015-10-12 08:20:17]

The patchset sent to the CQ was uploaded after l-g-t-m from drott@chromium.org
Link to the patchset: https://codereview.chromium.org/1395333002/#ps40001
(title: "Patch for landing")

[commit-bot: I haz the power, 2015-10-12 08:20:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1395333002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1395333002/40001

[commit-bot: I haz the power, 2015-10-12 08:57:06]

Committed patchset #2 (id:40001)

[commit-bot: I haz the power, 2015-10-12 08:58:15]

Patchset 2 (id:??) landed as
https://crrev.com/80b1511e005db3babec3ed84c23afbfda2513ee2
Cr-Commit-Position: refs/heads/master@{#353492}