[Sketch] Animations: Torpedo the old intrusive animation system.

Source/platform/scroll/ProgrammaticScrollAnimator.cpp

Index: Source/platform/scroll/ProgrammaticScrollAnimator.cpp
diff --git a/Source/platform/scroll/ProgrammaticScrollAnimator.cpp b/Source/platform/scroll/ProgrammaticScrollAnimator.cpp
index b90293681fd23d6067da66203133efd13bf38794..3ef7aa3136b0e97a1b2ba497b2058e017d2affa2 100644
--- a/Source/platform/scroll/ProgrammaticScrollAnimator.cpp
+++ b/Source/platform/scroll/ProgrammaticScrollAnimator.cpp
@@ -30,19 +30,14 @@ ProgrammaticScrollAnimator::ProgrammaticScrollAnimator(ScrollableArea* scrollabl
     , m_compositorAnimationId(0)
     , m_compositorAnimationGroupId(0)
 {
-    if (RuntimeEnabledFeatures::compositorAnimationTimelinesEnabled() && Platform::current()->compositorSupport()) {
-        m_compositorPlayer = adoptPtr(Platform::current()->compositorSupport()->createAnimationPlayer());
-        ASSERT(m_compositorPlayer);
-        m_compositorPlayer->setAnimationDelegate(this);
-    }
+    m_compositorPlayer = adoptPtr(Platform::current()->compositorSupport()->createAnimationPlayer());
+    ASSERT(m_compositorPlayer);
+    m_compositorPlayer->setAnimationDelegate(this);
 }
 
 ProgrammaticScrollAnimator::~ProgrammaticScrollAnimator()
 {
-    if (m_compositorPlayer) {
-        m_compositorPlayer->setAnimationDelegate(nullptr);
-        m_compositorPlayer.clear();
-    }
+    m_compositorPlayer->setAnimationDelegate(nullptr);
 }
 
 void ProgrammaticScrollAnimator::resetAnimationState()
@@ -138,13 +133,8 @@ void ProgrammaticScrollAnimator::updateCompositorAnimations()
         // animation is added below.
         ASSERT(m_runState == RunState::WaitingToCancelOnCompositor || m_runState == RunState::WaitingToSendToCompositor);
 
-        if (m_compositorPlayer) {
-            if (m_compositorPlayer->isLayerAttached())
-                m_compositorPlayer->removeAnimation(m_compositorAnimationId);
-        } else {
-            if (GraphicsLayer* layer = m_scrollableArea->layerForScrolling())
-                layer->removeAnimation(m_compositorAnimationId);
-        }
+        if (m_compositorPlayer->isLayerAttached())
+            m_compositorPlayer->removeAnimation(m_compositorAnimationId);
 
         m_compositorAnimationId = 0;
         m_compositorAnimationGroupId = 0;
@@ -164,15 +154,8 @@ void ProgrammaticScrollAnimator::updateCompositorAnimations()
                 int animationId = animation->id();
                 int animationGroupId = animation->group();
 
-                bool animatonAdded = false;
-                if (m_compositorPlayer && m_compositorPlayer->isLayerAttached()) {
+                if (m_compositorPlayer->isLayerAttached()) {
                     m_compositorPlayer->addAnimation(animation.leakPtr());
-                    animatonAdded = true;
-                } else {
-                    animatonAdded = m_scrollableArea->layerForScrolling()->addAnimation(animation.release());
-                }
-
-                if (animatonAdded) {
                     sentToCompositor = true;
                     m_runState = RunState::RunningOnCompositor;
                     m_compositorAnimationId = animationId;
@@ -193,11 +176,10 @@ void ProgrammaticScrollAnimator::updateCompositorAnimations()
 
 void ProgrammaticScrollAnimator::layerForCompositedScrollingDidChange(WebCompositorAnimationTimeline* timeline)
 {
-    if (m_compositorPlayer && timeline) {
-        if (m_compositorPlayer->isLayerAttached())
-            m_compositorPlayer->detachLayer();
-        timeline->playerDestroyed(*this);
-    }
+    if (m_compositorPlayer->isLayerAttached())
+        m_compositorPlayer->detachLayer();
+
+    timeline->playerDestroyed(*this);
 
     // If the composited scrolling layer is lost during a composited animation,
     // continue the animation on the main thread.
@@ -213,15 +195,19 @@ void ProgrammaticScrollAnimator::layerForCompositedScrollingDidChange(WebComposi
         }
     }
 
-    if (m_compositorPlayer && timeline && m_scrollableArea->layerForScrolling()) {
+    if (m_scrollableArea->layerForScrolling()) {
         timeline->playerAttached(*this);
         m_compositorPlayer->attachLayer(m_scrollableArea->layerForScrolling()->platformLayer());
     }
 }
 
-void ProgrammaticScrollAnimator::notifyCompositorAnimationFinished(int groupId)
+void ProgrammaticScrollAnimator::notifyAnimationStarted(double monotonicTime, int group)
 {
-    if (m_compositorAnimationGroupId != groupId)
+}
+
+void ProgrammaticScrollAnimator::notifyAnimationFinished(double monotonicTime, int group)
+{
+    if (m_compositorAnimationGroupId != group)
         return;
 
     m_compositorAnimationId = 0;
@@ -240,15 +226,6 @@ void ProgrammaticScrollAnimator::notifyCompositorAnimationFinished(int groupId)
     }
 }
 
-void ProgrammaticScrollAnimator::notifyAnimationStarted(double monotonicTime, int group)
-{
-}
-
-void ProgrammaticScrollAnimator::notifyAnimationFinished(double monotonicTime, int group)
-{
-    notifyCompositorAnimationFinished(group);
-}
-
 WebCompositorAnimationPlayer* ProgrammaticScrollAnimator::compositorPlayer() const
 {
     return m_compositorPlayer.get();