Merge pull request #16021 from twbs/visibility-block

rm `visibility` where redundant to `display`

less/component-animations.less

@@ -17,9 +17,8 @@
 
 .collapse {
   display: none;
-  visibility: hidden;
 
-  &.in      { display: block; visibility: visible; }
+  &.in      { display: block; }
   tr&.in    { display: table-row; }
   tbody&.in { display: table-row-group; }
 }

less/navbar.less

@@ -67,7 +67,6 @@
 
     &.collapse {
       display: block !important;
-      visibility: visible !important;
       height: auto !important;
       padding-bottom: 0; // Override default setting
       overflow: visible !important;

less/navs.less

@@ -223,11 +223,9 @@
 .tab-content {
   > .tab-pane {
     display: none;
-    visibility: hidden;
   }
   > .active {
     display: block;
-    visibility: visible;
   }
 }
 

less/tooltip.less

@@ -8,7 +8,6 @@
   position: absolute;
   z-index: @zindex-tooltip;
   display: block;
-  visibility: visible;
   // Reset font and text properties given new insertion method
   font-family: @font-family-base;
   font-size: @font-size-small;