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

cc/layers/render_surface_impl.h

Index: cc/layers/render_surface_impl.h
diff --git a/cc/layers/render_surface_impl.h b/cc/layers/render_surface_impl.h
index d6ab409a4b4900f51340669da71f9f803b1d7526..8cbc4fe0661633d36b672ffc31893a6bbc9f1b10 100644
--- a/cc/layers/render_surface_impl.h
+++ b/cc/layers/render_surface_impl.h
@@ -25,6 +25,8 @@ class DelegatedRendererLayerImpl;
 class QuadSink;
 class RenderPassSink;
 class LayerImpl;
+template <typename LayerType>
+class LayerIterator;
 
 struct AppendQuadsData;
 
@@ -174,7 +176,7 @@ class CC_EXPORT RenderSurfaceImpl {
   int target_render_surface_layer_index_history_;
   int current_layer_index_history_;
 
-  friend struct LayerIteratorActions;
+  friend class LayerIterator<LayerImpl>;
 
   DISALLOW_COPY_AND_ASSIGN(RenderSurfaceImpl);
 };