Re-enable WinEWS tests.

* Scripts/webkitpy/tool/commands/earlywarningsystem.py:
(WinEWS):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148299 268f45cc-cd09-0410-ab3c-d52691b4dbfc
REGRESSION (r138858): GIFs don't start playing when they come out of background tabs
https://bugs.webkit.org/show_bug.cgi?id=108864
<rdar://problem/13140489>

Reviewed by Antti Koivisto.

Don't repaint the world when animations resume; instead, FrameView
will cause all animated images to repaint. This line also had no effect for
TiledCoreAnimationDrawingArea, which does not implement setNeedsDisplay.

* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::resumeActiveDOMObjectsAndAnimations):

* loader/cache/CachedImage.cpp:
(WebCore::CachedImage::resumeAnimatingImagesForLoader): Added.
Iterate through all of the loader's cached resources. If they are bitmap images
which claim to be animatable, notify the image's observers that the animation advanced
by one frame. In reality, the image is still on the same frame, but will now be repainted,
restarting the animation loop.
* loader/cache/CachedImage.h:
* page/FrameView.cpp:
(WebCore::FrameView::setIsInWindow):
When the FrameView is brought into a window, repaint all animated images.
* platform/graphics/BitmapImage.cpp:
(WebCore::BitmapImage::canAnimate): Added. 
Return whether or not the image should animate (claims to animate, has not already
finished its animation, and has an ImageObserver) *and* has more than one frame.
* platform/graphics/BitmapImage.h:
(BitmapImage): Add canAnimate.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148300 268f45cc-cd09-0410-ab3c-d52691b4dbfc