[gtk+] viewport: share style context with pixelcache

[Christian Hergert <chergert src gnome org>]

commit 7c1ce9f3adabee70de886c6d32333650c691e97c
Author: Christian Hergert <christian hergert me>
Date:   Tue Sep 8 15:09:04 2015 -0700

    viewport: share style context with pixelcache
    
    This allows the pixel cache to opportunistically use CAIRO_CONTENT_COLOR
    instead of CAIRO_CONTENT_COLOR_ALPHA during surface creation.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=754658

 gtk/gtkviewport.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkviewport.c b/gtk/gtkviewport.c
index 6b842b4..9b96605 100644
--- a/gtk/gtkviewport.c
+++ b/gtk/gtkviewport.c
@@ -260,6 +260,7 @@ static void
 gtk_viewport_init (GtkViewport *viewport)
 {
   GtkViewportPrivate *priv;
+  GtkStyleContext *style_context;
 
   viewport->priv = gtk_viewport_get_instance_private (viewport);
   priv = viewport->priv;
@@ -276,6 +277,9 @@ gtk_viewport_init (GtkViewport *viewport)
 
   priv->pixel_cache = _gtk_pixel_cache_new ();
 
+  style_context = gtk_widget_get_style_context (GTK_WIDGET (viewport));
+  _gtk_pixel_cache_set_style_context (priv->pixel_cache, style_context);
+
   gtk_style_context_add_class (gtk_widget_get_style_context (GTK_WIDGET (viewport)), GTK_STYLE_CLASS_FRAME);
   viewport_set_adjustment (viewport, GTK_ORIENTATION_HORIZONTAL, NULL);
   viewport_set_adjustment (viewport, GTK_ORIENTATION_VERTICAL, NULL);