--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -2220,17 +2220,16 @@ GK_ATOM(forcemessagemanager, "forcemessa
 
 // Names for system metrics
 GK_ATOM(color_picker_available, "color-picker-available")
 GK_ATOM(scrollbar_start_backward, "scrollbar-start-backward")
 GK_ATOM(scrollbar_start_forward, "scrollbar-start-forward")
 GK_ATOM(scrollbar_end_backward, "scrollbar-end-backward")
 GK_ATOM(scrollbar_end_forward, "scrollbar-end-forward")
 GK_ATOM(scrollbar_thumb_proportional, "scrollbar-thumb-proportional")
-GK_ATOM(images_in_buttons, "images-in-buttons")
 GK_ATOM(overlay_scrollbars, "overlay-scrollbars")
 GK_ATOM(windows_default_theme, "windows-default-theme")
 GK_ATOM(mac_graphite_theme, "mac-graphite-theme")
 GK_ATOM(mac_lion_theme, "mac-lion-theme")
 GK_ATOM(mac_yosemite_theme, "mac-yosemite-theme")
 GK_ATOM(windows_compositor, "windows-compositor")
 GK_ATOM(windows_glass, "windows-glass")
 GK_ATOM(touch_enabled, "touch-enabled")
@@ -2251,17 +2250,16 @@ GK_ATOM(windows_theme_generic, "windows-
 
 // And the same again, as media query keywords.
 GK_ATOM(_moz_color_picker_available, "-moz-color-picker-available")
 GK_ATOM(_moz_scrollbar_start_backward, "-moz-scrollbar-start-backward")
 GK_ATOM(_moz_scrollbar_start_forward, "-moz-scrollbar-start-forward")
 GK_ATOM(_moz_scrollbar_end_backward, "-moz-scrollbar-end-backward")
 GK_ATOM(_moz_scrollbar_end_forward, "-moz-scrollbar-end-forward")
 GK_ATOM(_moz_scrollbar_thumb_proportional, "-moz-scrollbar-thumb-proportional")
-GK_ATOM(_moz_images_in_buttons, "-moz-images-in-buttons")
 GK_ATOM(_moz_overlay_scrollbars, "-moz-overlay-scrollbars")
 GK_ATOM(_moz_windows_default_theme, "-moz-windows-default-theme")
 GK_ATOM(_moz_mac_graphite_theme, "-moz-mac-graphite-theme")
 GK_ATOM(_moz_mac_lion_theme, "-moz-mac-lion-theme")
 GK_ATOM(_moz_mac_yosemite_theme, "-moz-mac-yosemite-theme")
 GK_ATOM(_moz_windows_compositor, "-moz-windows-compositor")
 GK_ATOM(_moz_windows_classic, "-moz-windows-classic")
 GK_ATOM(_moz_windows_glass, "-moz-windows-glass")

--- a/layout/style/nsCSSRuleProcessor.cpp
+++ b/layout/style/nsCSSRuleProcessor.cpp
@@ -1097,22 +1097,16 @@ InitSystemMetrics()
 
   metricResult =
     LookAndFeel::GetInt(LookAndFeel::eIntID_ScrollSliderStyle);
   if (metricResult != LookAndFeel::eScrollThumbStyle_Normal) {
     sSystemMetrics->AppendElement(nsGkAtoms::scrollbar_thumb_proportional);
   }
 
   metricResult =
-    LookAndFeel::GetInt(LookAndFeel::eIntID_ImagesInButtons);
-  if (metricResult) {
-    sSystemMetrics->AppendElement(nsGkAtoms::images_in_buttons);
-  }
-
-  metricResult =
     LookAndFeel::GetInt(LookAndFeel::eIntID_UseOverlayScrollbars);
   if (metricResult) {
     sSystemMetrics->AppendElement(nsGkAtoms::overlay_scrollbars);
   }
 
   metricResult =
     LookAndFeel::GetInt(LookAndFeel::eIntID_MenuBarDrag);
   if (metricResult) {

--- a/layout/style/nsMediaFeatures.cpp
+++ b/layout/style/nsMediaFeatures.cpp
@@ -672,24 +672,16 @@ nsMediaFeatures::features[] = {
     &nsGkAtoms::_moz_scrollbar_thumb_proportional,
     nsMediaFeature::eMinMaxNotAllowed,
     nsMediaFeature::eBoolInteger,
     nsMediaFeature::eNoRequirements,
     { &nsGkAtoms::scrollbar_thumb_proportional },
     GetSystemMetric
   },
   {
-    &nsGkAtoms::_moz_images_in_buttons,
-    nsMediaFeature::eMinMaxNotAllowed,
-    nsMediaFeature::eBoolInteger,
-    nsMediaFeature::eNoRequirements,
-    { &nsGkAtoms::images_in_buttons },
-    GetSystemMetric
-  },
-  {
     &nsGkAtoms::_moz_overlay_scrollbars,
     nsMediaFeature::eMinMaxNotAllowed,
     nsMediaFeature::eBoolInteger,
     nsMediaFeature::eNoRequirements,
     { &nsGkAtoms::overlay_scrollbars },
     GetSystemMetric
   },
   {

--- a/layout/style/test/test_media_queries.html
+++ b/layout/style/test/test_media_queries.html
@@ -619,85 +619,80 @@ function run() {
   should_not_apply("(grid: -1)");
 
   // System metrics
   expression_should_be_parseable("-moz-scrollbar-start-backward");
   expression_should_be_parseable("-moz-scrollbar-start-forward");
   expression_should_be_parseable("-moz-scrollbar-end-backward");
   expression_should_be_parseable("-moz-scrollbar-end-forward");
   expression_should_be_parseable("-moz-scrollbar-thumb-proportional");
-  expression_should_be_parseable("-moz-images-in-buttons");
   expression_should_be_parseable("-moz-overlay-scrollbars");
   expression_should_be_parseable("-moz-windows-default-theme");
   expression_should_be_parseable("-moz-mac-graphite-theme");
   expression_should_be_parseable("-moz-mac-lion-theme");
   expression_should_be_parseable("-moz-mac-yosemite-theme");
   expression_should_be_parseable("-moz-windows-compositor");
   expression_should_be_parseable("-moz-windows-classic");
   expression_should_be_parseable("-moz-windows-glass");
   expression_should_be_parseable("-moz-touch-enabled");
   expression_should_be_parseable("-moz-swipe-animation-enabled");
 
   expression_should_be_parseable("-moz-scrollbar-start-backward: 0");
   expression_should_be_parseable("-moz-scrollbar-start-forward: 0");
   expression_should_be_parseable("-moz-scrollbar-end-backward: 0");
   expression_should_be_parseable("-moz-scrollbar-end-forward: 0");
   expression_should_be_parseable("-moz-scrollbar-thumb-proportional: 0");
-  expression_should_be_parseable("-moz-images-in-buttons: 0");
   expression_should_be_parseable("-moz-overlay-scrollbars: 0");
   expression_should_be_parseable("-moz-windows-default-theme: 0");
   expression_should_be_parseable("-moz-mac-graphite-theme: 0");
   expression_should_be_parseable("-moz-mac-lion-theme: 0");
   expression_should_be_parseable("-moz-mac-yosemite-theme: 0");
   expression_should_be_parseable("-moz-windows-compositor: 0");
   expression_should_be_parseable("-moz-windows-classic: 0");
   expression_should_be_parseable("-moz-windows-glass: 0");
   expression_should_be_parseable("-moz-touch-enabled: 0");
   expression_should_be_parseable("-moz-swipe-animation-enabled: 0");
 
   expression_should_be_parseable("-moz-scrollbar-start-backward: 1");
   expression_should_be_parseable("-moz-scrollbar-start-forward: 1");
   expression_should_be_parseable("-moz-scrollbar-end-backward: 1");
   expression_should_be_parseable("-moz-scrollbar-end-forward: 1");
   expression_should_be_parseable("-moz-scrollbar-thumb-proportional: 1");
-  expression_should_be_parseable("-moz-images-in-buttons: 1");
   expression_should_be_parseable("-moz-overlay-scrollbars: 1");
   expression_should_be_parseable("-moz-windows-default-theme: 1");
   expression_should_be_parseable("-moz-mac-graphite-theme: 1");
   expression_should_be_parseable("-moz-mac-lion-theme: 1");
   expression_should_be_parseable("-moz-mac-yosemite-theme: 1");
   expression_should_be_parseable("-moz-windows-compositor: 1");
   expression_should_be_parseable("-moz-windows-classic: 1");
   expression_should_be_parseable("-moz-windows-glass: 1");
   expression_should_be_parseable("-moz-touch-enabled: 1");
   expression_should_be_parseable("-moz-swipe-animation-enabled: 1");
 
   expression_should_not_be_parseable("-moz-scrollbar-start-backward: -1");
   expression_should_not_be_parseable("-moz-scrollbar-start-forward: -1");
   expression_should_not_be_parseable("-moz-scrollbar-end-backward: -1");
   expression_should_not_be_parseable("-moz-scrollbar-end-forward: -1");
   expression_should_not_be_parseable("-moz-scrollbar-thumb-proportional: -1");
-  expression_should_not_be_parseable("-moz-images-in-buttons: -1");
   expression_should_not_be_parseable("-moz-overlay-scrollbars: -1");
   expression_should_not_be_parseable("-moz-windows-default-theme: -1");
   expression_should_not_be_parseable("-moz-mac-graphite-theme: -1");
   expression_should_not_be_parseable("-moz-mac-lion-theme: -1");
   expression_should_not_be_parseable("-moz-mac-yosemite-theme: -1");
   expression_should_not_be_parseable("-moz-windows-compositor: -1");
   expression_should_not_be_parseable("-moz-windows-classic: -1");
   expression_should_not_be_parseable("-moz-windows-glass: -1");
   expression_should_not_be_parseable("-moz-touch-enabled: -1");
   expression_should_not_be_parseable("-moz-swipe-animation-enabled: -1");
 
   expression_should_not_be_parseable("-moz-scrollbar-start-backward: true");
   expression_should_not_be_parseable("-moz-scrollbar-start-forward: true");
   expression_should_not_be_parseable("-moz-scrollbar-end-backward: true");
   expression_should_not_be_parseable("-moz-scrollbar-end-forward: true");
   expression_should_not_be_parseable("-moz-scrollbar-thumb-proportional: true");
-  expression_should_not_be_parseable("-moz-images-in-buttons: true");
   expression_should_not_be_parseable("-moz-overlay-scrollbars: true");
   expression_should_not_be_parseable("-moz-windows-default-theme: true");
   expression_should_not_be_parseable("-moz-mac-graphite-theme: true");
   expression_should_not_be_parseable("-moz-mac-lion-theme: true");
   expression_should_not_be_parseable("-moz-mac-yosemite-theme: true");
   expression_should_not_be_parseable("-moz-windows-compositor: true");
   expression_should_not_be_parseable("-moz-windows-classic: true");
   expression_should_not_be_parseable("-moz-windows-glass: true");

--- a/toolkit/content/xul.css
+++ b/toolkit/content/xul.css
@@ -110,24 +110,16 @@ button[type="repeat"] {
 button[type="menu"], button[type="panel"] {
   -moz-binding: url("chrome://global/content/bindings/button.xml#menu");
 }
 
 button[type="menu-button"] {
   -moz-binding: url("chrome://global/content/bindings/button.xml#menu-button");
 }
 
-%ifdef MOZ_WIDGET_GTK
-/********* detection of system setting to use icons in buttons ***********/
-button[label]:not([label=""]) > .button-box > .button-icon:not(:-moz-system-metric(images-in-buttons)),
-button[label]:not([label=""]) > .button-box > .box-inherit > .button-icon:not(:-moz-system-metric(images-in-buttons)) {
-  display: none;
-}
-%endif
-
 /********** toolbarbutton **********/
 
 toolbarbutton {
   -moz-binding: url("chrome://global/content/bindings/toolbarbutton.xml#toolbarbutton");
 }
 
 toolbarbutton.badged-button > toolbarbutton,
 toolbarbutton.badged-button {

--- a/toolkit/themes/linux/global/button.css
+++ b/toolkit/themes/linux/global/button.css
@@ -145,204 +145,8 @@ button[type="disclosure"] {
   list-style-image: url("chrome://global/skin/tree/twisty-clsd.png");
   min-width: 0px !important;
   background-color: transparent;
 }
 
 button[type="disclosure"][open="true"] {
   list-style-image: url("chrome://global/skin/tree/twisty-open.png"); 
 }
-
-/*
- * GNOME Stock Icon Styles
- */
-
-button[icon="accept"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-ok?size=button");
-}
-
-button[icon="accept"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-ok?size=button&state=disabled");
-}
-
-button[icon="cancel"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-cancel?size=button");
-}
-
-button[icon="cancel"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-cancel?size=button&state=disabled");
-}
-
-button[icon="help"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-help?size=button");
-}
-
-button[icon="help"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-help?size=button&state=disabled");
-}
-
-button[icon="open"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-open?size=button");
-}
-
-button[icon="open"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-open?size=button&state=disabled");
-}
-
-button[icon="save"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-save?size=button");
-}
-
-button[icon="save"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-save?size=button&state=disabled");
-}
-
-button[icon="find"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-find?size=button");
-}
-
-button[icon="find"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-find?size=button&state=disabled");
-}
-
-button[icon="clear"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-clear?size=button");
-}
-
-button[icon="clear"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-clear?size=button&state=disabled");
-}
-
-button[icon="yes"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-yes?size=button");
-}
-
-button[icon="yes"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-yes?size=button&state=disabled");
-}
-
-button[icon="no"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-no?size=button");
-}
-
-button[icon="no"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-no?size=button&state=disabled");
-}
-
-button[icon="apply"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-apply?size=button");
-}
-
-button[icon="apply"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-apply?size=button&state=disabled");
-}
-
-button[icon="close"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-close?size=button");
-}
-
-button[icon="close"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-close?size=button&state=disabled");
-}
-
-button[icon="print"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-print?size=button");
-}
-
-button[icon="print"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-print?size=button&state=disabled");
-}
-
-button[icon="add"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-add?size=button");
-}
-
-button[icon="add"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-add?size=button&state=disabled");
-}
-
-button[icon="remove"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-remove?size=button");
-}
-
-button[icon="remove"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-remove?size=button&state=disabled");
-}
-
-button[icon="refresh"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-refresh?size=button");
-}
-
-button[icon="refresh"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-refresh?size=button&state=disabled");
-}
-
-button[icon="revert"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-revert-to-saved?size=button");
-}
-
-button[icon="revert"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-revert-to-saved?size=button&state=disabled");
-}
-
-button[icon="go-forward"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-go-forward-ltr?size=button");
-}
-
-button[icon="go-forward"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-go-forward-ltr?size=button&state=disabled");
-}
-
-button[icon="go-forward"]:-moz-locale-dir(rtl) .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-go-forward-rtl?size=button");
-}
-
-button[icon="go-forward"]:-moz-locale-dir(rtl)[disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-go-forward-rtl?size=button&state=disabled");
-}
-
-button[icon="go-back"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-go-back-ltr?size=button");
-}
-
-button[icon="go-back"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-go-back-ltr?size=button&state=disabled");
-}
-
-button[icon="go-back"]:-moz-locale-dir(rtl) .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-go-back-rtl?size=button");
-}
-
-button[icon="go-back"]:-moz-locale-dir(rtl)[disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-go-back-rtl?size=button&state=disabled");
-}
-
-button[icon="properties"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-properties?size=button");
-}
-
-button[icon="properties"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-properties?size=button&state=disabled");
-}
-
-button[icon="select-font"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-select-font?size=button");
-}
-
-button[icon="select-font"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-select-font?size=button&state=disabled");
-}
-
-button[icon="select-color"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-color-picker?size=button");
-}
-
-button[icon="select-color"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-color-picker?size=button&state=disabled");
-}
-
-button[icon="network"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-network?size=button");
-}
-
-button[icon="network"][disabled="true"] .button-icon {
-  list-style-image: url("moz-icon://stock/gtk-network?size=button&state=disabled");
-}

--- a/widget/LookAndFeel.h
+++ b/widget/LookAndFeel.h
@@ -342,20 +342,16 @@ public:
      */
     eIntID_IMERawInputUnderlineStyle,
     eIntID_IMESelectedRawTextUnderlineStyle,
     eIntID_IMEConvertedTextUnderlineStyle,
     eIntID_IMESelectedConvertedTextUnderline,
     eIntID_SpellCheckerUnderlineStyle,
 
     /**
-     * If this metric != 0, show icons in buttons.
-     */
-    eIntID_ImagesInButtons,
-    /**
      * If this metric != 0, support window dragging on the menubar.
      */
     eIntID_MenuBarDrag,
     /**
      * Return the appropriate WindowsThemeIdentifier for the current theme.
      */
     eIntID_WindowsThemeIdentifier,
     /**

--- a/widget/gtk/gtk2drawing.c
+++ b/widget/gtk/gtk2drawing.c
@@ -3195,29 +3195,16 @@ moz_gtk_get_scrollbar_metrics(MozGtkScro
                           NULL);
 
     metrics->min_slider_size =
         GTK_RANGE(gHorizScrollbarWidget)->min_slider_size;
 
     return MOZ_GTK_SUCCESS;
 }
 
-gboolean
-moz_gtk_images_in_buttons()
-{
-    gboolean result;
-    GtkSettings* settings;
-
-    ensure_button_widget();
-    settings = gtk_widget_get_settings(gButtonWidget);
-
-    g_object_get(settings, "gtk-button-images", &result, NULL);
-    return result;
-}
-
 gint
 moz_gtk_widget_paint(WidgetNodeType widget, GdkDrawable* drawable,
                      GdkRectangle* rect, GdkRectangle* cliprect,
                      GtkWidgetState* state, gint flags,
                      GtkTextDirection direction)
 {
     switch (widget) {
     case MOZ_GTK_BUTTON:

--- a/widget/gtk/gtk3drawing.cpp
+++ b/widget/gtk/gtk3drawing.cpp
@@ -2616,28 +2616,16 @@ moz_gtk_get_scrollbar_metrics(MozGtkScro
         gtk_style_context_get(style, gtk_style_context_get_state(style),
                               "min-height", &metrics->min_slider_size, nullptr);
         ReleaseStyleContext(style);
     }
 
     return MOZ_GTK_SUCCESS;
 }
 
-gboolean
-moz_gtk_images_in_buttons()
-{
-    gboolean result;
-    GtkSettings* settings;
-
-    settings = gtk_widget_get_settings(GetWidget(MOZ_GTK_BUTTON));
-
-    g_object_get(settings, "gtk-button-images", &result, NULL);
-    return result;
-}
-
 /* cairo_t *cr argument has to be a system-cairo. */
 gint
 moz_gtk_widget_paint(WidgetNodeType widget, cairo_t *cr,
                      GdkRectangle* rect,
                      GtkWidgetState* state, gint flags,
                      GtkTextDirection direction)
 {
     /* A workaround for https://bugzilla.gnome.org/show_bug.cgi?id=694086

--- a/widget/gtk/gtkdrawing.h
+++ b/widget/gtk/gtkdrawing.h
@@ -500,22 +500,16 @@ GtkWidget* moz_gtk_get_scrollbar_widget(
 
 /**
  * Get the YTHICKNESS of a tab (notebook extension).
  */
 gint
 moz_gtk_get_tab_thickness(WidgetNodeType aNodeType);
 
 /**
- * Get a boolean which indicates whether or not to use images in buttons.
- * If TRUE, use images in buttons.
- */
-gboolean moz_gtk_images_in_buttons(void);
-
-/**
  * Get a boolean which indicates whether the theme draws scrollbar buttons.
  * If TRUE, draw scrollbar buttons.
  */
 gboolean moz_gtk_has_scrollbar_buttons(void);
 
 #if (MOZ_WIDGET_GTK == 2)
 #ifdef __cplusplus
 }

--- a/widget/gtk/nsLookAndFeel.cpp
+++ b/widget/gtk/nsLookAndFeel.cpp
@@ -780,19 +780,16 @@ nsLookAndFeel::GetIntImpl(IntID aID, int
         break;
     case eIntID_IMESelectedRawTextUnderlineStyle:
     case eIntID_IMESelectedConvertedTextUnderline:
         aResult = NS_STYLE_TEXT_DECORATION_STYLE_NONE;
         break;
     case eIntID_SpellCheckerUnderlineStyle:
         aResult = NS_STYLE_TEXT_DECORATION_STYLE_WAVY;
         break;
-    case eIntID_ImagesInButtons:
-        aResult = moz_gtk_images_in_buttons();
-        break;
     case eIntID_MenuBarDrag:
         aResult = sMenuSupportsDrag;
         break;
     case eIntID_ScrollbarButtonAutoRepeatBehavior:
         aResult = 1;
         break;
     case eIntID_SwipeAnimationEnabled:
         aResult = 0;