CC: Plumb LayerSettings parameter for cc::Layer construction.

content/public/test/layouttest_support.h

Index: content/public/test/layouttest_support.h
diff --git a/content/public/test/layouttest_support.h b/content/public/test/layouttest_support.h
index 8e75dfefead4b97917abf9f153955b34e96254e0..c4ad85d04cee52873a7dfe1bcfe4da5beb52c1d9 100644
--- a/content/public/test/layouttest_support.h
+++ b/content/public/test/layouttest_support.h
@@ -125,6 +125,10 @@ void DisableAutoResizeMode(RenderView* render_view,
 std::string DumpBackForwardList(std::vector<PageState>& page_state,
                                 size_t current_index);
 
+// Creates cc::TextureLayer for TestPlugin.
+scoped_refptr<cc::TextureLayer> CreateTextureLayerForMailbox(
+    cc::TextureLayerClient* client);
+
 // Instantiates WebLayerImpl for TestPlugin.
 blink::WebLayer* InstantiateWebLayer(scoped_refptr<cc::TextureLayer> layer);