Use an auxiliary list of animation controllers.

cc/test/layer_tree_test_common.cc

Index: cc/test/layer_tree_test_common.cc
diff --git a/cc/test/layer_tree_test_common.cc b/cc/test/layer_tree_test_common.cc
index 8be9cf95a54714ff710a6c5d4d30a04189c8cbd8..3f3ab27c37cd18c3ef5588de84e514a370104b20 100644
--- a/cc/test/layer_tree_test_common.cc
+++ b/cc/test/layer_tree_test_common.cc
@@ -162,12 +162,6 @@ public:
         return MockLayerTreeHostImpl::create(m_testHooks, settings(), client, proxy()).PassAs<cc::LayerTreeHostImpl>();
     }
 
-    virtual void didAddAnimation() OVERRIDE
-    {
-        LayerTreeHost::didAddAnimation();
-        m_testHooks->didAddAnimation();
-    }
-
     virtual void setNeedsCommit() OVERRIDE
     {
         if (!m_testStarted)
@@ -175,6 +169,12 @@ public:
         LayerTreeHost::setNeedsCommit();
     }
 
+    virtual void Register(cc::LayerAnimationController* controller) OVERRIDE
+    {
+        LayerTreeHost::Register(controller);
+        m_testHooks->didAddAnimation();
+    }
+
     void setTestStarted(bool started) { m_testStarted = started; }
 
     virtual void didDeferCommit() OVERRIDE
@@ -341,11 +341,6 @@ void ThreadedTest::postSetVisibleToMainThread(bool visible)
     m_mainThreadProxy->postTask(FROM_HERE, base::Bind(&ThreadedTest::dispatchSetVisible, base::Unretained(this), visible));
 }
 
-void ThreadedTest::postDidAddAnimationToMainThread()
-{
-    m_mainThreadProxy->postTask(FROM_HERE, base::Bind(&ThreadedTest::dispatchDidAddAnimation, base::Unretained(this)));
-}
-
 void ThreadedTest::doBeginTest()
 {
     m_client = ThreadedMockLayerTreeHostClient::create(this);
@@ -488,17 +483,6 @@ void ThreadedTest::dispatchComposite()
         m_layerTreeHost->composite();
 }
 
-void ThreadedTest::dispatchDidAddAnimation()
-{
-    DCHECK(!proxy() || proxy()->isMainThread());
-
-    if (m_finished)
-        return;
-
-    if (m_layerTreeHost.get())
-        m_layerTreeHost->didAddAnimation();
-}
-
 void ThreadedTest::runTest(bool threaded)
 {
     if (threaded) {