--- a/browser/base/content/browser-places.js
+++ b/browser/base/content/browser-places.js
@@ -28,17 +28,19 @@ var StarUI = {
     element.addEventListener("keypress", this);
     element.addEventListener("mousedown", this);
     element.addEventListener("mouseout", this);
     element.addEventListener("mousemove", this);
     element.addEventListener("compositionstart", this);
     element.addEventListener("compositionend", this);
     element.addEventListener("input", this);
     element.addEventListener("popuphidden", this);
+    element.addEventListener("popupshowing", this);
     element.addEventListener("popupshown", this);
+    element.addEventListener("transitionend", this);
     return this.panel = element;
   },
 
   // Array of command elements to disable when the panel is opened.
   get _blockedCommands() {
     delete this._blockedCommands;
     return this._blockedCommands =
       ["cmd_close", "cmd_closeWindow"].map(id => this._element(id));
@@ -191,16 +193,27 @@ var StarUI = {
           this._autoCloseTimer = setTimeout(() => {
             if (!this.panel.mozMatchesSelector(":hover")) {
               this.panel.hidePopup();
             }
           }, delay);
           this._autoCloseTimerEnabled = true;
         }
         break;
+      case "popupshowing":
+        if (Services.prefs.getBoolPref("toolkit.cosmeticAnimations.enabled")) {
+          this.panel.setAttribute("animating", "true");
+        }
+        break;
+      case "transitionend":
+        if (aEvent.propertyName == "transform" &&
+            aEvent.target == this.panel) {
+          this.panel.removeAttribute("animating");
+        }
+        break;
     }
   },
 
   _overlayLoaded: false,
   _overlayLoading: false,
   async showEditBookmarkPopup(aNode, aAnchorElement, aPosition, aIsNewBookmark) {
     // Slow double-clicks (not true double-clicks) shouldn't
     // cause the panel to flicker.

--- a/browser/base/content/browser.css
+++ b/browser/base/content/browser.css
@@ -1103,27 +1103,83 @@ toolbarpaletteitem[place="palette"] > #d
   -moz-appearance: none;
   -moz-binding: url("chrome://browser/content/places/menu.xml#places-popup-arrow");
   background: transparent;
   border: none;
   /* The popup inherits -moz-image-region from the button, must reset it */
   -moz-image-region: auto;
 }
 
+%ifdef MOZ_PHOTON_ANIMATIONS
 %ifdef MOZ_WIDGET_COCOA
 
 /* On Mac, use the properties "-moz-window-transform" and "-moz-window-opacity"
    instead of "transform" and "opacity" for these animations.
    The -moz-window* properties apply to the whole window including the window's
    shadow, and they don't affect the window's "shape", so the system doesn't
    have to recompute the shadow shape during the animation. This makes them a
    lot faster. In fact, Gecko no longer triggers shadow shape recomputations
    for repaints.
    These properties are not implemented on other platforms. */
 #BMB_bookmarksPopup {
+  -moz-window-opacity: 0;
+  -moz-window-transform: translateY(-70px);
+  transition-property: -moz-window-transform, -moz-window-opacity;
+  transition-duration: 0.18s, 0.18s;
+  transition-timing-function:
+    var(--animation-easing-function), ease-out;
+}
+
+#BMB_bookmarksPopup[side="bottom"] {
+  -moz-window-transform: translateY(70px);
+}
+
+#BMB_bookmarksPopup[animate="open"] {
+  -moz-window-opacity: 1.0;
+  transition-duration: 0.20s, 0.10s;
+  -moz-window-transform: none;
+  transition-timing-function:
+    var(--animation-easing-function), ease-in-out;
+}
+
+#BMB_bookmarksPopup[animate="cancel"] {
+  -moz-window-transform: none;
+}
+
+%elifndef MOZ_WIDGET_GTK
+
+#BMB_bookmarksPopup {
+  opacity: 0;
+  transform: translateY(-70px);
+  transition-property: transform, opacity;
+  transition-duration: 0.18s, 0.18s;
+  transition-timing-function:
+    var(--animation-easing-function), ease-out;
+}
+
+#BMB_bookmarksPopup[side="bottom"] {
+  transform: translateY(70px);
+}
+
+#BMB_bookmarksPopup[animate="open"] {
+  opacity: 1.0;
+  transition-duration: 0.20s, 0.10s;
+  transform: none;
+  transition-timing-function:
+    var(--animation-easing-function), ease-in-out;
+}
+
+#BMB_bookmarksPopup[animate="cancel"] {
+  transform: none;
+}
+%endif
+
+%else
+%ifdef MOZ_WIDGET_COCOA
+#BMB_bookmarksPopup {
   -moz-window-transform: scale(.4);
   -moz-window-opacity: 0;
   transition-property: -moz-window-transform, -moz-window-opacity;
   transition-duration: 0.15s;
   transition-timing-function: ease-out;
 }
 
 #BMB_bookmarksPopup[animate="open"] {
@@ -1189,16 +1245,17 @@ toolbarpaletteitem[place="palette"] > #d
   transform-origin: 20px bottom;
 }
 
 #BMB_bookmarksPopup[arrowposition="before_end"]:-moz-locale-dir(ltr),
 #BMB_bookmarksPopup[arrowposition="before_start"]:-moz-locale-dir(rtl) {
   transform-origin: calc(100% - 20px) bottom;
 }
 %endif
+%endif
 
 /* Customize mode */
 %ifndef MOZ_PHOTON_THEME
 #navigator-toolbox,
 #browser-bottombox,
 #content-deck {
   transition-property: margin-left, margin-right;
   transition-duration: 200ms;

--- a/toolkit/content/xul.css
+++ b/toolkit/content/xul.css
@@ -436,27 +436,88 @@ tooltip {
   white-space: pre-wrap;
   margin-top: 21px;
 }
 
 panel[type="arrow"] {
   -moz-binding: url("chrome://global/content/bindings/popup.xml#arrowpanel");
 }
 
+%ifdef MOZ_PHOTON_ANIMATIONS
 %ifdef MOZ_WIDGET_COCOA
 
 /* On Mac, use the properties "-moz-window-transform" and "-moz-window-opacity"
    instead of "transform" and "opacity" for these animations.
    The -moz-window* properties apply to the whole window including the window's
    shadow, and they don't affect the window's "shape", so the system doesn't
    have to recompute the shadow shape during the animation. This makes them a
    lot faster. In fact, Gecko no longer triggers shadow shape recomputations
    for repaints.
    These properties are not implemented on other platforms. */
 panel[type="arrow"]:not([animate="false"]) {
+  -moz-window-opacity: 0;
+  -moz-window-transform: translateY(-70px);
+  transition-property: -moz-window-transform, -moz-window-opacity;
+  transition-duration: 0.18s, 0.18s;
+  transition-timing-function:
+    var(--animation-easing-function), ease-out;
+}
+
+panel[type="arrow"][side="bottom"]:not([animate="false"]) {
+  -moz-window-transform: translateY(70px);
+}
+
+panel[type="arrow"][side][animate="open"] {
+  -moz-window-opacity: 1.0;
+  transition-duration: 0.20s, 0.10s;
+  -moz-window-transform: none;
+  transition-timing-function:
+    var(--animation-easing-function), ease-in-out;
+}
+
+panel[type="arrow"][animate="cancel"] {
+  -moz-window-transform: none;
+}
+
+%elifndef MOZ_WIDGET_GTK
+
+panel[type="arrow"]:not([animate="false"]) {
+  opacity: 0;
+  transform: translateY(-70px);
+  transition-property: transform, opacity;
+  transition-duration: 0.18s, 0.18s;
+  transition-timing-function:
+    var(--animation-easing-function), ease-out;
+}
+
+panel[type="arrow"][side="bottom"]:not([animate="false"]) {
+  transform: translateY(70px);
+}
+
+panel[type="arrow"][side][animate="open"] {
+  opacity: 1.0;
+  transition-duration: 0.20s, 0.10s;
+  transform: none;
+  transition-timing-function:
+    var(--animation-easing-function), ease-in-out;
+}
+
+panel[type="arrow"][animate="cancel"] {
+  transform: none;
+}
+
+%endif
+panel[type="arrow"][animating] {
+  pointer-events: none;
+}
+
+%else
+
+%ifdef MOZ_WIDGET_COCOA
+panel[type="arrow"]:not([animate="false"]) {
   -moz-window-transform: scale(.4);
   -moz-window-opacity: 0;
   transition-property: -moz-window-transform, -moz-window-opacity;
   transition-duration: 0.15s;
   transition-timing-function: ease-out;
 }
 
 panel[type="arrow"][animate="open"] {
@@ -563,16 +624,17 @@ panel[arrowposition="start_before"]:-moz
 }
 
 panel[arrowposition="end_after"]:-moz-locale-dir(ltr),
 panel[arrowposition="start_after"]:-moz-locale-dir(rtl) {
   transform-origin: left calc(100% - 20px);
 }
 
 %endif
+%endif
 
 %ifdef XP_MACOSX
 .statusbar-resizerpanel {
   display: none;
 }
 %else
 window[sizemode="maximized"] statusbarpanel.statusbar-resizerpanel {
   visibility: collapse;