Add DirectComposition overlay support.

ui/gl/dc_renderer_layer_params.cc

Index: ui/gl/dc_renderer_layer_params.cc
diff --git a/ui/gl/dc_renderer_layer_params.cc b/ui/gl/dc_renderer_layer_params.cc
index 6222c31c382aad2018e2d2d962ee5f8ecba996e6..9f451b5a5a42d99d5857c221f8def380790204dd 100644
--- a/ui/gl/dc_renderer_layer_params.cc
+++ b/ui/gl/dc_renderer_layer_params.cc
@@ -4,11 +4,13 @@
 
 #include "ui/gl/dc_renderer_layer_params.h"
 
+#include "ui/gl/gl_image.h"
+
 namespace ui {
 
 DCRendererLayerParams::DCRendererLayerParams(bool is_clipped,
                                              const gfx::Rect clip_rect,
-                                             unsigned sorting_context_id,
+                                             int z_order,
                                              const gfx::Transform& transform,
                                              gl::GLImage* image,
                                              const gfx::RectF& contents_rect,
@@ -19,7 +21,7 @@ DCRendererLayerParams::DCRendererLayerParams(bool is_clipped,
                                              unsigned filter)
     : is_clipped(is_clipped),
       clip_rect(clip_rect),
-      sorting_context_id(sorting_context_id),
+      z_order(z_order),
       transform(transform),
       image(image),
       contents_rect(contents_rect),