Remove root layer specialness in calculateDrawTransforms

cc/test/layer_tree_test_common.h

Index: cc/test/layer_tree_test_common.h
diff --git a/cc/test/layer_tree_test_common.h b/cc/test/layer_tree_test_common.h
index 91f95252c1bc912902b4eea8cace8df99e073650..1308f878ec1f15ab9055697efbbd87dd2fec14fb 100644
--- a/cc/test/layer_tree_test_common.h
+++ b/cc/test/layer_tree_test_common.h
@@ -75,7 +75,7 @@ public:
     void endTestAfterDelay(int delayMilliseconds);
 
     void postSetNeedsAnimateToMainThread();
-    void postAddAnimationToMainThread();
+    void postAddAnimationToMainThread(cc::Layer*);
     void postAddInstantAnimationToMainThread();
     void postSetNeedsCommitToMainThread();
     void postAcquireLayerTextures();
@@ -102,7 +102,7 @@ protected:
 
     void dispatchSetNeedsAnimate();
     void dispatchAddInstantAnimation();
-    void dispatchAddAnimation();
+    void dispatchAddAnimation(cc::Layer*);
     void dispatchSetNeedsAnimateAndCommit();
     void dispatchSetNeedsCommit();
     void dispatchAcquireLayerTextures();