--- a/gfx/src/nsThemeConstants.h
+++ b/gfx/src/nsThemeConstants.h
@@ -277,8 +277,10 @@
 #define NS_THEME_WINDOW_BUTTON_MAXIMIZE                    238
 #define NS_THEME_WINDOW_BUTTON_RESTORE                     239
 #define NS_THEME_WINDOW_BUTTON_BOX                         240
 #define NS_THEME_WINDOW_BUTTON_BOX_MAXIMIZED               241
 
 // moz-apperance style used in setting proper glass margins
 #define NS_THEME_WIN_EXCLUDE_GLASS                         242
 
+#define NS_THEME_MAC_VIBRANCY_LIGHT                        243
+#define NS_THEME_MAC_VIBRANCY_DARK                         244

--- a/layout/base/nsDisplayList.cpp
+++ b/layout/base/nsDisplayList.cpp
@@ -2432,16 +2432,18 @@ nsDisplayThemedBackground::nsDisplayThem
   // Perform necessary RegisterThemeGeometry
   switch (disp->mAppearance) {
     case NS_THEME_MOZ_MAC_UNIFIED_TOOLBAR:
     case NS_THEME_TOOLBAR:
     case NS_THEME_WINDOW_TITLEBAR:
     case NS_THEME_WINDOW_BUTTON_BOX:
     case NS_THEME_MOZ_MAC_FULLSCREEN_BUTTON:
     case NS_THEME_WINDOW_BUTTON_BOX_MAXIMIZED:
+    case NS_THEME_MAC_VIBRANCY_LIGHT:
+    case NS_THEME_MAC_VIBRANCY_DARK:
       RegisterThemeGeometry(aBuilder, aFrame);
       break;
     case NS_THEME_WIN_BORDERLESS_GLASS:
     case NS_THEME_WIN_GLASS:
       aBuilder->SetGlassDisplayItem(this);
       break;
   }
 

--- a/layout/style/nsCSSKeywordList.h
+++ b/layout/style/nsCSSKeywordList.h
@@ -683,16 +683,18 @@ CSS_KEY(-moz-window-button-close, _moz_w
 CSS_KEY(-moz-window-button-minimize, _moz_window_button_minimize)
 CSS_KEY(-moz-window-button-maximize, _moz_window_button_maximize)
 CSS_KEY(-moz-window-button-restore, _moz_window_button_restore)
 CSS_KEY(-moz-window-button-box, _moz_window_button_box)
 CSS_KEY(-moz-window-button-box-maximized, _moz_window_button_box_maximized)
 CSS_KEY(-moz-mac-help-button, _moz_mac_help_button)
 CSS_KEY(-moz-mac-unified-toolbar, _moz_mac_unified_toolbar)
 CSS_KEY(-moz-win-exclude-glass, _moz_win_exclude_glass)
+CSS_KEY(-moz-mac-vibrancy-light, _moz_mac_vibrancy_light)
+CSS_KEY(-moz-mac-vibrancy-dark, _moz_mac_vibrancy_dark)
 CSS_KEY(alphabetic, alphabetic)
 CSS_KEY(bevel, bevel)
 CSS_KEY(butt, butt)
 CSS_KEY(central, central)
 CSS_KEY(crispedges, crispedges)
 //CSS_KEY(end, end)
 CSS_KEY(evenodd, evenodd)
 CSS_KEY(geometricprecision, geometricprecision)

--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -723,16 +723,18 @@ const KTableValue nsCSSProps::kAppearanc
   eCSSKeyword__moz_window_frame_bottom,       NS_THEME_WINDOW_FRAME_BOTTOM,
   eCSSKeyword__moz_window_button_close,       NS_THEME_WINDOW_BUTTON_CLOSE,
   eCSSKeyword__moz_window_button_minimize,    NS_THEME_WINDOW_BUTTON_MINIMIZE,
   eCSSKeyword__moz_window_button_maximize,    NS_THEME_WINDOW_BUTTON_MAXIMIZE,
   eCSSKeyword__moz_window_button_restore,     NS_THEME_WINDOW_BUTTON_RESTORE,
   eCSSKeyword__moz_window_button_box,         NS_THEME_WINDOW_BUTTON_BOX,
   eCSSKeyword__moz_window_button_box_maximized, NS_THEME_WINDOW_BUTTON_BOX_MAXIMIZED,
   eCSSKeyword__moz_win_exclude_glass,         NS_THEME_WIN_EXCLUDE_GLASS,
+  eCSSKeyword__moz_mac_vibrancy_light,        NS_THEME_MAC_VIBRANCY_LIGHT,
+  eCSSKeyword__moz_mac_vibrancy_dark,         NS_THEME_MAC_VIBRANCY_DARK,
   eCSSKeyword_UNKNOWN,-1
 };
 
 const KTableValue nsCSSProps::kBackfaceVisibilityKTable[] = {
   eCSSKeyword_visible, NS_STYLE_BACKFACE_VISIBILITY_VISIBLE,
   eCSSKeyword_hidden, NS_STYLE_BACKFACE_VISIBILITY_HIDDEN,
   eCSSKeyword_UNKNOWN,-1
 };