cc: Clean up iterator template to only take 1 parameter.

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 56e7eb56578e2a594a252d1d0f452fb7587b0d3f..7f9f67403d1834969ab8be9b953ebad92e2ce077 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -770,12 +770,9 @@ DrawSwapReadbackResult::DrawResult LayerTreeHostImpl::CalculateRenderPasses(
         &frame->non_occluding_screen_space_rects);
   }
 
-  // Add quads to the Render passes in FrontToBack order to allow for testing
+  // Add quads to the Render passes in front-to-back order to allow for testing
   // occlusion and performing culling during the tree walk.
-  typedef LayerIterator<LayerImpl,
-                        LayerImplList,
-                        RenderSurfaceImpl,
-                        LayerIteratorActions::FrontToBack> LayerIteratorType;
+  typedef LayerIterator<LayerImpl> LayerIteratorType;
 
   // Typically when we are missing a texture and use a checkerboard quad, we
   // still draw the frame. However when the layer being checkerboarded is moving