--- a/devtools/shared/css/generated/properties-db.js
+++ b/devtools/shared/css/generated/properties-db.js
@@ -195,16 +195,18 @@ exports.CSS_PROPERTIES = {
       "-moz-mac-disclosure-button-closed",
       "-moz-mac-disclosure-button-open",
       "-moz-mac-fullscreen-button",
       "-moz-mac-help-button",
       "-moz-mac-source-list",
       "-moz-mac-source-list-selection",
       "-moz-mac-vibrancy-dark",
       "-moz-mac-vibrancy-light",
+      "-moz-mac-vibrant-titlebar-dark",
+      "-moz-mac-vibrant-titlebar-light",
       "-moz-win-borderless-glass",
       "-moz-win-browsertabbar-toolbox",
       "-moz-win-communications-toolbox",
       "-moz-win-exclude-glass",
       "-moz-win-glass",
       "-moz-win-media-toolbox",
       "-moz-window-button-box",
       "-moz-window-button-box-maximized",

--- a/gfx/src/nsThemeConstants.h
+++ b/gfx/src/nsThemeConstants.h
@@ -289,16 +289,18 @@ enum ThemeWidgetType : uint8_t {
   NS_THEME_WINDOW_BUTTON_BOX,
   NS_THEME_WINDOW_BUTTON_BOX_MAXIMIZED,
 
   // moz-apperance style used in setting proper glass margins
   NS_THEME_WIN_EXCLUDE_GLASS,
 
   NS_THEME_MAC_VIBRANCY_LIGHT,
   NS_THEME_MAC_VIBRANCY_DARK,
+  NS_THEME_MAC_VIBRANT_TITLEBAR_LIGHT,
+  NS_THEME_MAC_VIBRANT_TITLEBAR_DARK,
   NS_THEME_MAC_DISCLOSURE_BUTTON_OPEN,
   NS_THEME_MAC_DISCLOSURE_BUTTON_CLOSED,
 
   NS_THEME_GTK_INFO_BAR,
   NS_THEME_MAC_SOURCE_LIST,
   NS_THEME_MAC_SOURCE_LIST_SELECTION,
   NS_THEME_MAC_ACTIVE_SOURCE_LIST_SELECTION,
 

--- a/layout/style/nsCSSKeywordList.h
+++ b/layout/style/nsCSSKeywordList.h
@@ -755,16 +755,18 @@ CSS_KEY(-moz-window-button-minimize, _mo
 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-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(-moz-mac-vibrant-titlebar-light, _moz_mac_vibrant_titlebar_light)
+CSS_KEY(-moz-mac-vibrant-titlebar-dark, _moz_mac_vibrant_titlebar_dark)
 CSS_KEY(-moz-mac-disclosure-button-closed, _moz_mac_disclosure_button_closed)
 CSS_KEY(-moz-mac-disclosure-button-open, _moz_mac_disclosure_button_open)
 CSS_KEY(-moz-mac-source-list, _moz_mac_source_list)
 CSS_KEY(-moz-mac-source-list-selection, _moz_mac_source_list_selection)
 CSS_KEY(-moz-mac-active-source-list-selection, _moz_mac_active_source_list_selection)
 CSS_KEY(alphabetic, alphabetic)
 CSS_KEY(bevel, bevel)
 CSS_KEY(butt, butt)

--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -854,16 +854,18 @@ const KTableEntry nsCSSProps::kAppearanc
   { 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__moz_mac_vibrant_titlebar_light, NS_THEME_MAC_VIBRANT_TITLEBAR_LIGHT },
+  { eCSSKeyword__moz_mac_vibrant_titlebar_dark,  NS_THEME_MAC_VIBRANT_TITLEBAR_DARK },
   { eCSSKeyword__moz_mac_disclosure_button_open,   NS_THEME_MAC_DISCLOSURE_BUTTON_OPEN },
   { eCSSKeyword__moz_mac_disclosure_button_closed, NS_THEME_MAC_DISCLOSURE_BUTTON_CLOSED },
   { eCSSKeyword__moz_gtk_info_bar,              NS_THEME_GTK_INFO_BAR },
   { eCSSKeyword__moz_mac_source_list,           NS_THEME_MAC_SOURCE_LIST },
   { eCSSKeyword__moz_mac_source_list_selection, NS_THEME_MAC_SOURCE_LIST_SELECTION },
   { eCSSKeyword__moz_mac_active_source_list_selection, NS_THEME_MAC_ACTIVE_SOURCE_LIST_SELECTION },
   { eCSSKeyword_UNKNOWN,                        -1 }
 };