Blink Compositor Animation: Introduce CompositorAnimationHost correctly.

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index a3385911ce5d3f9c65ae83beed3686e6af0325c1..ade550149e2af9d6696c9f397c0102c17151d2ed 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -102,6 +102,7 @@
 #include "platform/PlatformMouseEvent.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/UserGestureIndicator.h"
+#include "platform/animation/CompositorAnimationHost.h"
 #include "platform/exported/WebActiveGestureAnimation.h"
 #include "platform/fonts/FontCache.h"
 #include "platform/geometry/FloatRect.h"
@@ -2528,6 +2529,7 @@ void WebViewImpl::willCloseLayerTreeView() {
     page()->willCloseLayerTreeView(*m_layerTreeView);
 
   setRootLayer(nullptr);
+  m_compositorAnimationHost = nullptr;
 
   m_mutator = nullptr;
   m_layerTreeView = nullptr;
@@ -3946,22 +3948,24 @@ void WebViewImpl::scheduleAnimationForWidget() {
 
 void WebViewImpl::attachCompositorAnimationTimeline(
     CompositorAnimationTimeline* timeline) {
-  if (m_layerTreeView)
-    m_layerTreeView->attachCompositorAnimationTimeline(
-        timeline->animationTimeline());
+  if (m_compositorAnimationHost)
+    m_compositorAnimationHost->addTimeline(timeline);
 }
 
 void WebViewImpl::detachCompositorAnimationTimeline(
     CompositorAnimationTimeline* timeline) {
-  if (m_layerTreeView)
-    m_layerTreeView->detachCompositorAnimationTimeline(
-        timeline->animationTimeline());
+  if (m_compositorAnimationHost)
+    m_compositorAnimationHost->removeTimeline(timeline);
 }
 
 void WebViewImpl::initializeLayerTreeView() {
   if (m_client) {
     m_client->initializeLayerTreeView();
     m_layerTreeView = m_client->widgetClient()->layerTreeView();
+    if (m_layerTreeView && m_layerTreeView->compositorAnimationHost()) {
+      m_compositorAnimationHost = WTF::makeUnique<CompositorAnimationHost>(
+          m_layerTreeView->compositorAnimationHost());
+    }
   }
 
   if (WebDevToolsAgentImpl* devTools = mainFrameDevToolsAgentImpl())