[BlackBerry] Accelerated animation regression with GL renderer
https://bugs.webkit.org/show_bug.cgi?id=114685

Reviewed by Rob Buis.

Internally reviewed by Filip Spacek.

GL renderer changed the assumption made in accelerated animation
code that rendering the contents of AC layer tiles would be the
slow operation. By starting animations after the slow operation,
the appearance of the animation could be made smooth.

Rendering tiles may still be slow, but now something else can be
slow too: drawing display lists to backing. And it's running on
the compositing thread, can happen at any time and will interrupt
accelerated animations.

Improved the situation by calling an API for updating backing to
schedule the delay at a convenient time. We try to update backing
before starting animations. However, future backing updates can
still interrupt the running animation and cause dropped frames.

Further improvements to animation smoothness will probably require
optimizations in the GL renderer.

* Api/WebPage.cpp:
(BlackBerry::WebKit::WebPagePrivate::WebPagePrivate):
(BlackBerry::WebKit::WebPagePrivate::commitRootLayer):
(BlackBerry::WebKit::WebPagePrivate::commitRootLayerIfNeeded):
* Api/WebPage_p.h:
(WebPagePrivate):
* WebKitSupport/FrameLayers.cpp:
(BlackBerry::WebKit::FrameLayers::notifyAnimationsStarted):
(WebKit):
* WebKitSupport/FrameLayers.h:
(FrameLayers):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148512 268f45cc-cd09-0410-ab3c-d52691b4dbfc