Bug 1489743 - Fix and clean up .toolbarbutton-menu-dropmarker styling after dropmarker.css changes. r=ntim

toolkit/themes/linux/global/toolbarbutton.css

@@ -69,10 +69,6 @@ toolbarbutton:-moz-lwtheme:not(:hover):not([checked="true"]):not([open="true"]):
 
 .toolbarbutton-menu-dropmarker {
   -moz-appearance: toolbarbutton-dropdown !important;
-  list-style-image: none;
-  -moz-image-region: auto;
-  padding: 0;
-  margin: 0;
 }
 
 .toolbarbutton-menu-dropmarker[disabled="true"] {

toolkit/themes/osx/global/toolbarbutton.css

@@ -30,10 +30,7 @@ toolbarbutton[disabled="true"][open="true"] {
 
 .toolbarbutton-menu-dropmarker {
   -moz-appearance: none !important;
-  border: none !important;
-  background-color: transparent !important;
   list-style-image: url("chrome://global/skin/arrow/arrow-dn.png");
-  padding: 0;
   padding-inline-start: 2px;
   width: auto;
 }

toolkit/themes/windows/global/toolbarbutton.css

@@ -92,10 +92,11 @@ toolbarbutton[checked="true"]:not([disabled="true"]) {
 
 .toolbarbutton-menu-dropmarker {
   -moz-appearance: none !important;
-  padding: 0;
-  width: auto;
-  height: auto;
-  margin-top: 1px;
+  list-style-image: url("chrome://global/skin/icons/arrow-dropdown-12.svg");
+  -moz-context-properties: fill;
+  fill: currentColor;
+  width: 12px;
+  height: 12px;
 }
 
 /* ::::: toolbarbutton badged ::::: */