REGRESSION (r163928): Animated GIFs are not resumed when translated into view using -webkit-transform
https://bugs.webkit.org/show_bug.cgi?id=139672
<rdar://problem/19260797>

Reviewed by Antti Koivisto.

Source/WebCore:

After r163928, animated GIFs were not resumed when translated into view
using '-webkit-transform' CSS property.

This broke animated gifs on the mobile version of weibo.com (which is
one of the most popular blogging sites in China) on iPhone. e.g.
http://m.weibo.cn/page/tpl?containerid=1005052150182731_-_WEIBO_SECOND_PROFILE_WEIBO&itemid=&title=全部微博

This patch calls FrameView::resumeVisibleImageAnimationsIncludingSubframes()
after style recalc so that we resume animated images if they become visible
after the style has changed. Doing so after layout wouldn't work because
no layout happens in this case.

Test: fast/images/animated-gif-webkit-transform.html

* dom/Document.cpp:
(WebCore::Document::recalcStyle):

LayoutTests:

Add a layout test to verity that animated images are properly paused /
resumed when translated in and out of view using '-webkit-transform'
CSS property.

* fast/images/animated-gif-webkit-transform-expected.txt: Added.
* fast/images/animated-gif-webkit-transform.html: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@177360 268f45cc-cd09-0410-ab3c-d52691b4dbfc