Fix issues with right border of the lower section as well as some CSS...

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 67 matching lines @@
 
 .filler {
   pointer-events: none;
 }
 
 .filler .thumbnail-wrapper {
   visibility: visible;
   border: 3px solid hsl(213, 60%, 92%);
 }
 
+.list > .filler * {
+  visibility: hidden !important;
+}
+
 .filler .thumbnail {
   visibility: inherit;
   border: 1px solid white;
   padding: 0;
   background-color: hsl(213, 60%, 92%);
 }
 
 .edit-bar {
   display: -webkit-box;
   -webkit-box-orient: horizontal;
@@ skipping 159 matching lines @@
   /* delay border radius transition as much as the edit bar slide delay */
   -webkit-transition-delay: 0, 0, 0, .5s, 0;
 }
 
 .thumbnail-container:focus > .edit-mode-border,
 .thumbnail-container:hover > .edit-mode-border {
   background-color: hsl(213, 66%, 57%);
   -webkit-box-shadow: 0px 2px 2px hsla(0, 0%, 0%, .5);
 }
 
-.dragging {
-  -webkit-transition: none;
+.dragging,
+.dragging * {
+  -webkit-transition: none !important;
 }
 
 .dragging > .title {
-  opacity: 0 !important;
+  opacity: 0;
 }
 
 .list > .dragging > .title {
   opacity: 1;
 }
 
 .hide {
   opacity: 0 !important;
   visibility: hidden !important;
 }
@@ skipping 215 matching lines @@
   -webkit-column-count: 2;
   -webkit-column-gap: 20px;
   height: 120px;
 }
 
 #recent-activities.large > .item-container {
   -webkit-column-count: 4;
 }
 
 .section {
-  -webkit-box-flex: 1;
-  width: 50%;
   display: inline-block;
 }
 
 #view-toolbar {
   -webkit-user-select: none;
   text-align: right;
   position: relative;
   top: 35px;
 }
 
@@ skipping 197 matching lines @@
   }
 
   #t3, #t7 {
     left: 534px;
   }
 
   #t4, #t5, #t6, #t7 {
     top: 147px;
   }
 }