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 0d7cfa9e05f282f1d19cb474ad31f780c190d062..8f6d9da1b25d931b29ee65c945c05ac9a14f425e 100644
--- a/content/public/test/layouttest_support.h
+++ b/content/public/test/layouttest_support.h
@@ -130,6 +130,10 @@ 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);