Bug 1250704 - use style from WidgetStyleCache for tooltip colors. r=stransky

MozReview-Commit-ID: 9xzL8ckxTRQ

--HG--
extra : transplant_source : %CB_%B9f%FD%10/%CD%5D%AF%85e%BE%A1%25psL%0A%0A

widget/gtk/nsLookAndFeel.cpp

@@ -31,6 +31,7 @@
 
 #if MOZ_WIDGET_GTK != 2
 #include <cairo-gobject.h>
+#include "WidgetStyleCache.h"
 #endif
 
 using mozilla::LookAndFeel;
@@ -1135,15 +1136,15 @@ nsLookAndFeel::Init()
     gtk_style_context_get_color(style, GTK_STATE_FLAG_NORMAL, &color);
     sMozWindowText = GDK_RGBA_TO_NS_RGBA(color);
     gtk_style_context_restore(style);
+    g_object_unref(style);
 
     // tooltip foreground and background
-    gtk_style_context_add_class(style, GTK_STYLE_CLASS_TOOLTIP);
-    gtk_style_context_add_class(style, GTK_STYLE_CLASS_BACKGROUND);
+    style = ClaimStyleContext(MOZ_GTK_TOOLTIP);
     gtk_style_context_get_background_color(style, GTK_STATE_FLAG_NORMAL, &color);
     sInfoBackground = GDK_RGBA_TO_NS_RGBA(color);
     gtk_style_context_get_color(style, GTK_STATE_FLAG_NORMAL, &color);
     sInfoText = GDK_RGBA_TO_NS_RGBA(color);
-    g_object_unref(style);
+    ReleaseStyleContext(style);
 
     // menu foreground & menu background
     GtkWidget *accel_label = gtk_accel_label_new("M");