We tested and it's broken. I will add a testcase shortly
Created attachment 32099 [details] test case This test case should be able to pause and continue the animations using the arrow keys. But they always animate
Created attachment 33720 [details] Patch with test
Sending LayoutTests/ChangeLog Sending LayoutTests/animations/animation-test-helpers.js Adding LayoutTests/animations/play-state-expected.txt Adding LayoutTests/animations/play-state.html Sending LayoutTests/platform/mac/fast/css/getComputedStyle/computed-style-expected.txt Sending LayoutTests/platform/mac/fast/css/getComputedStyle/computed-style-without-renderer-expected.txt Sending LayoutTests/svg/css/getComputedStyle-basic-expected.txt Sending WebCore/ChangeLog Sending WebCore/css/CSSComputedStyleDeclaration.cpp Sending WebCore/css/CSSParser.cpp Sending WebCore/css/CSSParser.h Sending WebCore/css/CSSPropertyNames.in Sending WebCore/css/CSSStyleSelector.cpp Sending WebCore/css/CSSStyleSelector.h Sending WebCore/platform/animation/Animation.h Sending WebCore/rendering/style/RenderStyleConstants.h Transmitting file data ................ Committed revision 46547.