--- a/browser/base/content/browser.css
+++ b/browser/base/content/browser.css
@@ -351,17 +351,16 @@ toolbarpaletteitem {
   display: none !important;
 }
 %endif
 
 #main-window[inFullscreen][inDOMFullscreen] #navigator-toolbox,
 #main-window[inFullscreen][inDOMFullscreen] #fullscr-toggler,
 #main-window[inFullscreen][inDOMFullscreen] #sidebar-box,
 #main-window[inFullscreen][inDOMFullscreen] #sidebar-splitter,
-#main-window[inFullscreen][inDOMFullscreen] #developer-toolbar,
 #main-window[inFullscreen]:not([OSXLionFullscreen]) toolbar:not([fullscreentoolbar=true]),
 #main-window[inFullscreen] #global-notificationbox,
 #main-window[inFullscreen] #high-priority-global-notificationbox {
   visibility: collapse;
 }
 
 #navigator-toolbox[fullscreenShouldAnimate] {
   transition: 1.5s margin-top ease-out;
@@ -1033,40 +1032,16 @@ browser[tabmodalPromptShowing] {
 }
 
 #statuspanel-inner {
   height: 3em;
   width: 100%;
   -moz-box-align: end;
 }
 
-/* gcli */
-
-html|*#gcli-tooltip-frame,
-html|*#gcli-output-frame,
-#gcli-output,
-#gcli-tooltip {
-  overflow-x: hidden;
-}
-
-.gclitoolbar-input-node,
-.gclitoolbar-complete-node {
-  direction: ltr;
-}
-
-#developer-toolbar-toolbox-button[error-count] > .toolbarbutton-icon {
-  display: none;
-}
-
-#developer-toolbar-toolbox-button[error-count]:before {
-  content: attr(error-count);
-  display: -moz-box;
-  -moz-box-pack: center;
-}
-
 /* Translation */
 notification[value="translation"] {
   -moz-binding: url("chrome://browser/content/translation-infobar.xml#translationbar");
 }
 
 /*** Visibility of downloads indicator controls ***/
 
 /* Bug 924050: If we've loaded the indicator, for now we hide it in the menu panel,

--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -554,35 +554,16 @@ notification[value="translation"] menuli
   border-top-left-radius: .3em;
   margin-left: 1em;
 }
 
 %include ../shared/fullscreen/warning.inc.css
 %include ../shared/ctrlTab.inc.css
 %include ../shared/plugin-doorhanger.inc.css
 
-.gcli-panel {
-  padding: 0;
-}
-
-.gclitoolbar-input-node > .textbox-input-box > html|*.textbox-input::-moz-selection {
-  color: hsl(210,11%,16%);
-}
-
-/* Error counter */
-
-#developer-toolbar-toolbox-button[error-count]:before {
-  color: #FDF3DE;
-  min-width: 16px;
-  text-shadow: none;
-  background-image: linear-gradient(#B4211B, #8A1915);
-  border-radius: 1px;
-  margin-inline-end: 2px;
-}
-
 /* Customization mode */
 
 %include ../shared/customizableui/customizeMode.inc.css
 
 /* End customization mode */
 
 %include ../shared/UITour.inc.css
 

--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -1030,30 +1030,16 @@ html|*.addon-webext-perm-list {
 /* On mac, the popup notification contents are indented by default and so
   the default closebutton margins from notification.css require adjustment */
 
 .click-to-play-plugins-notification-description-box > .popup-notification-closebutton {
   margin-inline-end: -6px;
   margin-top: -7px;
 }
 
-.gclitoolbar-input-node > .textbox-input-box > html|*.textbox-input::-moz-selection {
-  color: hsl(210,11%,16%);
-}
-
-/* Error counter */
-
-#developer-toolbar-toolbox-button[error-count]:before {
-  color: #FDF3DE;
-  min-width: 16px;
-  text-shadow: none;
-  background-image: linear-gradient(#B4211B, #8A1915);
-  border-radius: 1px;
-}
-
 /* Customization mode */
 
 %include ../shared/customizableui/customizeMode.inc.css
 
 /* End customization mode */
 
 /* Private browsing and accessibility indicators */
 

--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -951,27 +951,16 @@ notification[value="translation"] {
   */
   margin-left: 1em;
 }
 
 %include ../shared/fullscreen/warning.inc.css
 %include ../shared/ctrlTab.inc.css
 %include ../shared/plugin-doorhanger.inc.css
 
-/* Error counter */
-
-#developer-toolbar-toolbox-button[error-count]:before {
-  color: #FDF3DE;
-  min-width: 16px;
-  text-shadow: none;
-  background-image: linear-gradient(#B4211B, #8A1915);
-  border-radius: 1px;
-  margin-inline-end: 5px;
-}
-
 /* Customization mode */
 
 %include ../shared/customizableui/customizeMode.inc.css
 
 /**
  * This next rule is a hack to disable subpixel anti-aliasing on all
  * labels during the customize mode transition. Subpixel anti-aliasing
  * on Windows with Direct2D layers acceleration is particularly slow to