--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -1341,17 +1341,16 @@ var gBrowserInit = {
       if (width < TARGET_WIDTH && height < TARGET_HEIGHT) {
         document.documentElement.setAttribute("sizemode", "maximized");
       }
     }
 
     if (!window.toolbar.visible) {
       // adjust browser UI for popups
       gURLBar.setAttribute("readonly", "true");
-      gURLBar.setAttribute("enablehistory", "false");
     }
 
     // Misc. inits.
     TabletModeUpdater.init();
     CombinedStopReload.ensureInitialized();
     gPrivateBrowsingUI.init();
     BrowserPageActions.init();
     gAccessibilityServiceIndicator.init();

--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -774,17 +774,16 @@
                      autocompletesearch="unifiedcomplete"
                      autocompletesearchparam="enable-actions"
                      autocompletepopup="PopupAutoCompleteRichResult"
                      completeselectedindex="true"
                      shrinkdelay="250"
                      tabscrolling="true"
                      showcommentcolumn="true"
                      showimagecolumn="true"
-                     enablehistory="true"
                      newlines="stripsurroundingwhitespace"
                      ontextentered="this.handleCommand(param);"
                      ontextreverted="return this.handleRevert();"
                      pageproxystate="invalid">
               <!-- Use onclick instead of normal popup= syntax since the popup
                    code fires onmousedown, and hence eats our favicon drag events. -->
               <box id="identity-box" role="button"
                    align="center"

--- a/browser/base/content/urlbarBindings.xml
+++ b/browser/base/content/urlbarBindings.xml
@@ -43,20 +43,20 @@ file, You can obtain one at http://mozil
                       xbl:inherits="tooltiptext=inputtooltiptext,value,maxlength,disabled,size,readonly,placeholder,tabindex,accesskey,focused,textoverflow"/>
         </xul:hbox>
         <xul:image anonid="urlbar-go-button"
                    class="urlbar-go-button urlbar-icon"
                    onclick="gURLBar.handleCommand(event);"
                    tooltiptext="&goEndCap.tooltip;"
                    xbl:inherits="pageproxystate,parentfocused=focused,usertyping"/>
         <xul:dropmarker anonid="historydropmarker"
-                        class="autocomplete-history-dropmarker urlbar-history-dropmarker urlbar-icon"
+                        class="urlbar-history-dropmarker urlbar-icon chromeclass-toolbar-additional"
                         tooltiptext="&urlbar.openHistoryPopup.tooltip;"
                         allowevents="true"
-                        xbl:inherits="open,enablehistory,parentfocused=focused,usertyping"/>
+                        xbl:inherits="open,parentfocused=focused,usertyping"/>
         <children includes="hbox"/>
       </xul:hbox>
       <xul:popupset anonid="popupset"
                     class="autocomplete-result-popupset"/>
       <children includes="toolbarbutton"/>
     </content>
 
     <implementation implements="nsIObserver, nsIDOMEventListener">
@@ -124,16 +124,26 @@ file, You can obtain one at http://mozil
               "gURLBar.select(); goDoCommand('cmd_paste'); gURLBar.handleCommand();");
           cxmenu.insertBefore(pasteAndGo, insertLocation.nextSibling);
         }
 
         this.popup.addEventListener("popupshowing", () => {
           this._enableOrDisableOneOffSearches();
         }, {capturing: true, once: true});
 
+        // history dropmarker open state
+        this.popup.addEventListener("popupshowing", () => {
+          this.setAttribute("open", "true");
+        });
+        this.popup.addEventListener("popuphidden", () => {
+          requestAnimationFrame(() => {
+            this.removeAttribute("open");
+          });
+        });
+
         // The autocomplete controller uses heuristic on some internal caches
         // to handle cases like backspace, autofill or repeated searches.
         // Ensure to clear those internal caches when switching tabs.
         gBrowser.tabContainer.addEventListener("TabSelect", this);
       ]]></constructor>
 
       <destructor><![CDATA[
         this._prefs.removeObserver("", this);
@@ -1506,20 +1516,26 @@ file, You can obtain one at http://mozil
             this._pressedNoActionKeys.has(event.keyCode)) {
           this._pressedNoActionKeys.delete(event.keyCode);
           if (this._pressedNoActionKeys.size == 0)
             this._clearNoActions();
         }
       ]]></handler>
 
       <handler event="mousedown"><![CDATA[
-        // Eventually show the opt-out notification even if the location bar is
-        // empty, focused, and the user clicks on it.
-        if (event.button == 0 && this.focused && this.textValue == "") {
-          this.maybeShowSearchSuggestionsNotificationOnFocus(true);
+        if (event.button == 0) {
+          if (event.originalTarget.getAttribute("anonid") == "historydropmarker") {
+            this.toggleHistoryPopup();
+          }
+
+          // Eventually show the opt-out notification even if the location bar is
+          // empty, focused, and the user clicks on it.
+          if (this.focused && this.textValue == "") {
+            this.maybeShowSearchSuggestionsNotificationOnFocus(true);
+          }
         }
       ]]></handler>
 
       <handler event="focus"><![CDATA[
         if (event.originalTarget == this.inputField) {
           this._hideURLTooltip();
           this.formatValue();
           if (this.getAttribute("pageproxystate") != "valid") {

--- a/browser/components/sessionstore/SessionStore.jsm
+++ b/browser/components/sessionstore/SessionStore.jsm
@@ -3967,23 +3967,21 @@ var SessionStoreInternal = {
     WINDOW_HIDEABLE_FEATURES.forEach(function(aItem) {
       aWindow[aItem].visible = hidden.indexOf(aItem) == -1;
     });
 
     if (aWinData.isPopup) {
       this._windows[aWindow.__SSi].isPopup = true;
       if (aWindow.gURLBar) {
         aWindow.gURLBar.readOnly = true;
-        aWindow.gURLBar.setAttribute("enablehistory", "false");
       }
     } else {
       delete this._windows[aWindow.__SSi].isPopup;
       if (aWindow.gURLBar) {
         aWindow.gURLBar.readOnly = false;
-        aWindow.gURLBar.setAttribute("enablehistory", "true");
       }
     }
 
     aWindow.setTimeout(() => {
       this.restoreDimensions(aWindow,
         +(aWinData.width || 0),
         +(aWinData.height || 0),
         "screenX" in aWinData ? +aWinData.screenX : NaN,

--- a/browser/components/sessionstore/test/browser_495495.js
+++ b/browser/components/sessionstore/test/browser_495495.js
@@ -18,29 +18,25 @@ function test() {
         let state2 = ss.getWindowState(newWin);
 
         function testState(state, expected, callback) {
           let win = openDialog(location, "_blank", "chrome,all,dialog=no");
           promiseWindowLoaded(win).then(() => {
 
             is(win.gURLBar.readOnly, false,
                "URL bar should not be read-only before setting the state");
-            is(win.gURLBar.getAttribute("enablehistory"), "true",
-               "URL bar autocomplete should be enabled before setting the state");
             ss.setWindowState(win, state, true);
             is(win.gURLBar.readOnly, expected.readOnly,
                "URL bar read-only state should be restored correctly");
-            is(win.gURLBar.getAttribute("enablehistory"), expected.enablehistory,
-               "URL bar autocomplete state should be restored correctly");
 
             BrowserTestUtils.closeWindow(win).then(callback);
           });
         }
 
         BrowserTestUtils.closeWindow(newWin).then(() => {
-          testState(state1, {readOnly: false, enablehistory: "true"}, function() {
-            testState(state2, {readOnly: true, enablehistory: "false"}, finish);
+          testState(state1, {readOnly: false}, function() {
+            testState(state2, {readOnly: true}, finish);
           });
         });
       });
     });
   });
 }

--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -152,35 +152,29 @@ menuitem.bookmark-item {
   list-style-image: url("chrome://global/skin/icons/Restore.gif");
 }
 #close-button {
   list-style-image: url("chrome://global/skin/icons/Close.gif");
 }
 
 /* Location bar */
 
-#urlbar {
-  /* override textbox[enablehistory="true"] styling: */
-  background-color: -moz-field;
-}
-
 %include ../shared/urlbar-searchbar.inc.css
 
 #urlbar:not(:-moz-lwtheme):not([focused="true"]),
 .searchbar-textbox:not(:-moz-lwtheme):not([focused="true"]) {
   border-color: ThreeDShadow;
 }
 
 #urlbar[focused="true"],
 .searchbar-textbox[focused="true"] {
   border-color: Highlight;
 }
 
 .urlbar-textbox-container {
-  -moz-appearance: none;
   -moz-box-align: stretch;
 }
 
 /* ::::: URL Bar Zoom Reset Button ::::: */
 @keyframes urlbar-zoom-reset-pulse {
   0% {
     transform: scale(0);
   }

--- a/browser/themes/shared/urlbar-searchbar.inc.css
+++ b/browser/themes/shared/urlbar-searchbar.inc.css
@@ -220,16 +220,21 @@
 }
 
 .urlbar-history-dropmarker {
   -moz-appearance: none;
   list-style-image: url(chrome://global/skin/icons/arrow-dropdown-16.svg);
   transition: opacity 0.15s ease;
 }
 
+/* Avoid re-opening the popup when the dropmarker is clicked while the popup is still open. */
+.urlbar-history-dropmarker[open] {
+  pointer-events: none;
+}
+
 #urlbar[switchingtabs] > .urlbar-textbox-container > .urlbar-history-dropmarker {
   transition: none;
 }
 
 #nav-bar:not([customizing="true"]) > #nav-bar-customization-target > #urlbar-container:not(:hover) > #urlbar:not([focused]) > .urlbar-textbox-container > .urlbar-history-dropmarker {
   opacity: 0;
 }
 

--- a/toolkit/content/widgets/autocomplete.xml
+++ b/toolkit/content/widgets/autocomplete.xml
@@ -26,20 +26,16 @@
           <children/>
           <html:input anonid="input" class="autocomplete-textbox textbox-input"
                       allowevents="true"
                       xbl:inherits="tooltiptext=inputtooltiptext,value,type=inputtype,maxlength,disabled,size,readonly,placeholder,tabindex,accesskey,mozactionhint"/>
         </xul:hbox>
         <children includes="hbox"/>
       </xul:hbox>
 
-      <xul:dropmarker anonid="historydropmarker" class="autocomplete-history-dropmarker"
-                      allowevents="true"
-                      xbl:inherits="open,enablehistory,parentfocused=focused"/>
-
       <xul:popupset anonid="popupset" class="autocomplete-result-popupset"/>
 
       <children includes="toolbarbutton"/>
     </content>
 
     <implementation implements="nsIAutoCompleteInput, nsIDOMXULMenuListElement">
       <field name="mController">null</field>
       <field name="mSearchNames">null</field>
@@ -396,33 +392,16 @@
       <method name="closePopup">
         <body><![CDATA[
           this.popup.closePopup();
         ]]></body>
       </method>
 
       <method name="showHistoryPopup">
         <body><![CDATA[
-          // history dropmarker pushed state
-          function cleanup(popup) {
-            popup.removeEventListener("popupshowing", onShow);
-          }
-          function onShow(event) {
-            var popup = event.target, input = popup.input;
-            cleanup(popup);
-            input.setAttribute("open", "true");
-            function onHide() {
-              input.removeAttribute("open");
-              popup.removeEventListener("popuphiding", onHide);
-            }
-            popup.addEventListener("popuphiding", onHide);
-          }
-          this.popup.addEventListener("popupshowing", onShow);
-          setTimeout(cleanup, 1000, this.popup);
-
           // Store our "normal" maxRows on the popup, so that it can reset the
           // value when the popup is hidden.
           this.popup._normalMaxRows = this.maxRows;
 
           // Increase our maxRows temporarily, since we want the dropdown to
           // be bigger in this case. The popup's popupshowing/popuphiding
           // handlers will take care of resetting this.
           this.maxRows = this.maxDropMarkerRows;
@@ -432,20 +411,17 @@
             this.focus();
           this.attachController();
           this.mController.startSearch("");
         ]]></body>
       </method>
 
       <method name="toggleHistoryPopup">
         <body><![CDATA[
-          // If this method is called on the same event tick as the popup gets
-          // hidden, do nothing to avoid re-opening the popup when the drop
-          // marker is clicked while the popup is still open.
-          if (!this.popup.isPopupHidingTick && !this.popup.popupOpen)
+          if (!this.popup.popupOpen)
             this.showHistoryPopup();
           else
             this.closePopup();
         ]]></body>
       </method>
 
       <!-- ::::::::::::: event dispatching ::::::::::::: -->
 
@@ -907,32 +883,28 @@
     </implementation>
   </binding>
 
   <binding id="autocomplete-base-popup" role="none"
 extends="chrome://global/content/bindings/popup.xml#popup">
     <implementation implements="nsIAutoCompletePopup">
       <field name="mInput">null</field>
       <field name="mPopupOpen">false</field>
-      <field name="mIsPopupHidingTick">false</field>
 
       <!-- =================== nsIAutoCompletePopup =================== -->
 
       <property name="input" readonly="true"
                 onget="return this.mInput"/>
 
       <property name="overrideValue" readonly="true"
                 onget="return null;"/>
 
       <property name="popupOpen" readonly="true"
                 onget="return this.mPopupOpen;"/>
 
-      <property name="isPopupHidingTick" readonly="true"
-                onget="return this.mIsPopupHidingTick;"/>
-
       <method name="closePopup">
         <body>
           <![CDATA[
           if (this.mPopupOpen) {
             this.hidePopup();
             this.removeAttribute("width");
           }
         ]]>
@@ -1029,24 +1001,16 @@ extends="chrome://global/content/binding
         if (this.selectedIndex == -1)
           isListActive = false;
         var controller = this.view.QueryInterface(Components.interfaces.nsIAutoCompleteController);
         controller.stopSearch();
 
         this.removeAttribute("autocompleteinput");
         this.mPopupOpen = false;
 
-        // Prevent opening popup from historydropmarker mousedown handler
-        // on the same event tick the popup is hidden by the same mousedown
-        // event.
-        this.mIsPopupHidingTick = true;
-        setTimeout(() => {
-          this.mIsPopupHidingTick = false;
-        }, 0);
-
         // Reset the maxRows property to the cached "normal" value (if there's
         // any), and reset normalMaxRows so that we can detect whether it was set
         // by the input when the popupshowing handler runs.
 
         // Null-check this.mInput; see bug 1017914
         if (this.mInput && this._normalMaxRows > 0) {
           this.mInput.maxRows = this._normalMaxRows;
         }
@@ -2605,17 +2569,9 @@ extends="chrome://global/content/binding
     <content>
       <xul:hbox flex="1" class="tree-bodybox">
         <children/>
       </xul:hbox>
       <xul:scrollbar xbl:inherits="collapsed=hidescrollbar" orient="vertical" class="tree-scrollbar"/>
     </content>
   </binding>
 
-  <binding id="history-dropmarker" extends="chrome://global/content/bindings/general.xml#dropmarker">
-    <handlers>
-      <handler event="mousedown" button="0"><![CDATA[
-        document.getBindingParent(this).toggleHistoryPopup();
-      ]]></handler>
-    </handlers>
-  </binding>
-
 </bindings>

--- a/toolkit/content/xul.css
+++ b/toolkit/content/xul.css
@@ -829,20 +829,16 @@ panel[type="autocomplete"] {
 .autocomplete-history-popup {
   -moz-binding: url("chrome://global/content/autocomplete.xml#autocomplete-history-popup");
 }
 
 .autocomplete-treebody {
   -moz-binding: url("chrome://global/content/autocomplete.xml#autocomplete-treebody");
 }
 
-.autocomplete-history-dropmarker {
-  -moz-binding: url("chrome://global/content/autocomplete.xml#history-dropmarker");
-}
-
 panel[type="autocomplete-richlistbox"] {
   -moz-binding: url("chrome://global/content/bindings/autocomplete.xml#autocomplete-rich-result-popup");
 }
 
 .autocomplete-richlistbox {
   -moz-binding: url("chrome://global/content/bindings/autocomplete.xml#autocomplete-richlistbox");
   -moz-user-focus: ignore;
 }
@@ -896,25 +892,16 @@ panel[type="autocomplete-richlistbox"] {
   -moz-box-orient: vertical;
   overflow: -moz-hidden-unscrollable;
 }
 
 .autocomplete-treerows {
   -moz-binding: url("chrome://global/content/bindings/autocomplete.xml#autocomplete-treerows");
 }
 
-.autocomplete-history-dropmarker {
-  display: none;
-}
-
-.autocomplete-history-dropmarker[enablehistory="true"] {
-  display: -moz-box;
-  -moz-binding: url("chrome://global/content/bindings/autocomplete.xml#history-dropmarker");
-}
-
 %endif
 
 /* the C++ implementation of widgets is too eager to make popups visible.
    this causes problems (bug 120155 and others), thus this workaround: */
 popup[type="autocomplete"][hidden="true"] {
   visibility: hidden;
 }
 

--- a/toolkit/themes/linux/global/autocomplete.css
+++ b/toolkit/themes/linux/global/autocomplete.css
@@ -12,34 +12,24 @@
 /* ::::: autocomplete ::::: */
 
 /* .padded is used by autocomplete widgets that don't have an icon. Gross. -dwh */
 textbox:not(.padded) {
   cursor: default;
   padding: 0;
 }
 
-textbox[enablehistory="true"] {
-  -moz-appearance: none;
-  border: 0;
-  background-color: transparent;
-}
-
 textbox[nomatch="true"][highlightnonmatches="true"] {
   color: red;
 }
 
 .autocomplete-textbox-container {
   -moz-box-align: center;
 }
 
-textbox[enablehistory="true"] > .autocomplete-textbox-container {
-  -moz-appearance: menulist-textfield;
-}
-
 textbox:not(.padded) .textbox-input-box {
   margin: 0 3px;
 }
 
 .textbox-input-box {
   -moz-box-align: center;
 }