cc: Compute animation scale on demand

cc/test/layer_tree_host_common_test.h

Index: cc/test/layer_tree_host_common_test.h
diff --git a/cc/test/layer_tree_host_common_test.h b/cc/test/layer_tree_host_common_test.h
index e4f16d3987eb0b61e96ed8fba54cf20691058ac7..1d38e71b6d973ca8bdfb62c4e6b9864a4ae8cdfd 100644
--- a/cc/test/layer_tree_host_common_test.h
+++ b/cc/test/layer_tree_host_common_test.h
@@ -142,6 +142,22 @@ class LayerTreeHostCommonTest : public LayerTreeHostCommonTestBase,
       layer_impl->layer_tree_impl()->DidUpdateScrollOffset(
           layer_impl->id(), layer_impl->transform_tree_index());
   }
+
+  static float GetMaximumAnimationScale(LayerImpl* layer_impl) {
+    return layer_impl->layer_tree_impl()
+        ->property_trees()
+        ->GetAnimationScales(layer_impl->transform_tree_index(),
+                             layer_impl->layer_tree_impl())
+        .maximum_animation_scale;
+  }
+
+  static float GetStartingAnimationScale(LayerImpl* layer_impl) {
+    return layer_impl->layer_tree_impl()
+        ->property_trees()
+        ->GetAnimationScales(layer_impl->transform_tree_index(),
+                             layer_impl->layer_tree_impl())
+        .starting_animation_scale;
+  }
 };
 
 }  // namespace cc