Refactor MutatorHostClient from LayerTreeHost to LayerTree.

third_party/WebKit/Source/platform/testing/WebLayerTreeViewImplForTesting.cpp

Index: third_party/WebKit/Source/platform/testing/WebLayerTreeViewImplForTesting.cpp
diff --git a/third_party/WebKit/Source/platform/testing/WebLayerTreeViewImplForTesting.cpp b/third_party/WebKit/Source/platform/testing/WebLayerTreeViewImplForTesting.cpp
index 287d11be6d9178d5f7f7111d493b59d82be353f9..b268ab637593c600e5bcbcd247ebe7047843371d 100644
--- a/third_party/WebKit/Source/platform/testing/WebLayerTreeViewImplForTesting.cpp
+++ b/third_party/WebKit/Source/platform/testing/WebLayerTreeViewImplForTesting.cpp
@@ -77,14 +77,14 @@ void WebLayerTreeViewImplForTesting::clearRootLayer()
 
 void WebLayerTreeViewImplForTesting::attachCompositorAnimationTimeline(cc::AnimationTimeline* compositorTimeline)
 {
-    ASSERT(m_layerTreeHost->animation_host());
-    m_layerTreeHost->animation_host()->AddAnimationTimeline(compositorTimeline);
+    DCHECK(m_layerTreeHost->GetLayerTree()->animation_host());
+    m_layerTreeHost->GetLayerTree()->animation_host()->AddAnimationTimeline(compositorTimeline);
 }
 
 void WebLayerTreeViewImplForTesting::detachCompositorAnimationTimeline(cc::AnimationTimeline* compositorTimeline)
 {
-    ASSERT(m_layerTreeHost->animation_host());
-    m_layerTreeHost->animation_host()->RemoveAnimationTimeline(compositorTimeline);
+    DCHECK(m_layerTreeHost->GetLayerTree()->animation_host());
+    m_layerTreeHost->GetLayerTree()->animation_host()->RemoveAnimationTimeline(compositorTimeline);
 }
 
 void WebLayerTreeViewImplForTesting::setViewportSize(const WebSize& unusedDeprecated, const WebSize& deviceViewportSize)