Web Animations: Remove legacy animations engine.

Source/core/core.gypi

Index: Source/core/core.gypi
diff --git a/Source/core/core.gypi b/Source/core/core.gypi
index 7181e6d30a23dcda61540dacfe0300bddd30f86f..b1088cee440f3cfd7c7e33907dce1d0348bbf3ba 100644
--- a/Source/core/core.gypi
+++ b/Source/core/core.gypi
@@ -1078,18 +1078,6 @@
             'frame/SuspendableTimer.cpp',
             'frame/SuspendableTimer.h',
             'frame/UseCounter.cpp',
-            'frame/animation/AnimationBase.cpp',
-            'frame/animation/AnimationBase.h',
-            'frame/animation/AnimationController.cpp',
-            'frame/animation/AnimationControllerPrivate.h',
-            'frame/animation/CSSPropertyAnimation.cpp',
-            'frame/animation/CSSPropertyAnimation.h',
-            'frame/animation/CompositeAnimation.cpp',
-            'frame/animation/CompositeAnimation.h',
-            'frame/animation/ImplicitAnimation.cpp',
-            'frame/animation/ImplicitAnimation.h',
-            'frame/animation/KeyframeAnimation.cpp',
-            'frame/animation/KeyframeAnimation.h',
             'inspector/AsyncCallStackTracker.cpp',
             'inspector/AsyncCallStackTracker.h',
             'inspector/BindingVisitors.h',
@@ -1579,8 +1567,6 @@
             'rendering/TextAutosizer.h',
             'rendering/TrailingFloatsRootInlineBox.h',
             'rendering/VerticalPositionCache.h',
-            'rendering/animation/WebAnimationProvider.cpp',
-            'rendering/animation/WebAnimationProvider.h',
             'rendering/break_lines.cpp',
             'rendering/break_lines.h',
             'rendering/line/BreakingContext.cpp',