Fixing display: none; title for zoom

web/viewer.css

@@ -176,7 +176,10 @@ body {
 }
 
 .toolbarButton > span {
-  display: none;
+  display: inline-block;
+  width: 0;
+  height: 0;
+  overflow: hidden;
 }
 
 .toolbarButton[disabled] {

web/viewer.html

@@ -119,7 +119,7 @@
                      </button>
                   </div>
                   <span class="dropdownToolbarButton">
-                     <select id="scaleSelect" onchange="PDFView.parseScale(this.value);" oncontextmenu="return false;" tabindex="9">
+                     <select id="scaleSelect" onchange="PDFView.parseScale(this.value);" title="Zoom" oncontextmenu="return false;" tabindex="9">
                       <option id="pageAutoOption" value="auto" selected="selected">Automatic Zoom</option>
                       <option value="page-actual">Actual Size</option>
                       <option id="pageFitOption" value="page-fit">Fit Page</option>