Check renderability of images in a (-webkit-)cross-fade before using

Check renderability of images in a (-webkit-)cross-fade before using

If the image fails to decode or otherwise trigger an error, we don't
want to render it, since it will render (or measure) the "broken image"
placeholder.

BUG=111512
Committed: https://crrev.com/b7cdac20905928fa67fbe650f3c3e4b431c50a2f
git-svn-id: svn://svn.chromium.org/blink/trunk@202122 bbb929c8-8fbe-4397-9dbb-9b2b20218538

[fs, 2015-09-10 14:58:55]

fs@opera.com changed reviewers:
+ chrishtr@chromium.org, fmalita@chromium.org

[f(malita), 2015-09-10 16:18:34]

lgtm

[fs, 2015-09-11 08:20:29]

The CQ bit was checked by fs@opera.com

[commit-bot: I haz the power, 2015-09-11 08:20:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1334713002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1334713002/20001

[commit-bot: I haz the power, 2015-09-11 08:59:40]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=202122

[commit-bot: I haz the power, 2015-09-23 12:20:34]

Patchset 2 (id:??) landed as
https://crrev.com/b7cdac20905928fa67fbe650f3c3e4b431c50a2f