Tweaks for promo messages on NTP

chrome/browser/resources/new_new_tab.css

 html {
   /* This is needed because of chrome://theme/css/new_tab.css */
   height: 100%;
 }
 
 body {
   margin: 0;
 }
 
 #main {
@@ skipping 672 matching lines @@
   text-align: center;
 }
 
 #attribution {
   margin: 10px 0;
 }
 
 /* promotions line */
 #bottom-right-promo {
   position: absolute;
-  display: block;
   width: 180px;
   height: 131px;
   border: 0;
   bottom: 0px;
   right: 0px;
+  z-index: -1;
 }
 
 #footer {
   position: fixed;
-  bottom: 0px;
+  bottom: 0;
   left: 0px;
   text-align: center;
   width: 100%;
-  display: block;
+  -webkit-transition: bottom .15s;
+}
+
+#footer.hide-footer {
+  bottom: -40px;
 }
 
 #promo-line {
   background-color: hsl(52, 100%, 80%);
   border: 1px solid rgb(211, 211, 211);
   -webkit-border-radius: 6px;
   padding: 7px 10px;
   white-space: nowrap;
   display: inline-block;
   color: black;
@@ skipping 66 matching lines @@
   }
 
   #notification > * {
     max-width: 300px;
   }
 
   #notification > span > .blacklist-title {
     max-width: 15ex;
   }
 }