Mac Overlays: Plumb through GL solid color overlay support

ui/gl/gl_surface.h

Index: ui/gl/gl_surface.h
diff --git a/ui/gl/gl_surface.h b/ui/gl/gl_surface.h
index 5d98253910d4993e51517e0d68a344f0d016bff8..e327306ef5f71bfb2c5e55183a4e5bb585ed52dd 100644
--- a/ui/gl/gl_surface.h
+++ b/ui/gl/gl_surface.h
@@ -140,7 +140,13 @@ class GL_EXPORT GLSurface : public base::RefCounted<GLSurface> {
                                     GLImage* image,
                                     const Rect& bounds_rect,
                                     const RectF& crop_rect);
-
+  // Schedule a solid color overlay plane to be shown at swap time.
+  virtual bool ScheduleSolidColorOverlayPlane(int z_order,
+                                              const Rect& bounds_rect,
+                                              float red,
+                                              float green,
+                                              float blue,
+                                              float alpha);
   virtual bool IsSurfaceless() const;
 
   // Create a GL surface that renders directly to a view.