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

chrome/browser/resources/new_new_tab.js

 
 // Helpers
 
 function $(id) {
   return document.getElementById(id);
 }
 
 // TODO(arv): Remove these when classList is available in HTML5.
 // https://bugs.webkit.org/show_bug.cgi?id=20709
 function hasClass(el, name) {
@@ skipping 678 matching lines @@
   var recentShown = shownSections & Section.RECENT;
   var tipsShown = shownSections & Section.TIPS;
 
   if (recentShown || tipsShown) {
     lowerSectionsElement.style.height = '198px';
     lowerSectionsElement.style.opacity = '';
   } else {
     lowerSectionsElement.style.height = lowerSectionsElement.style.opacity = 0;
   }
 
+  // Even when the width is set to 0 it will take up 2px due to the border. We
+  // compensate by setting the margin to -2px.
   if (recentShown && tipsShown) {
     var w = (totalWidth - spacing) / 2;
     recentElement.style.width = tipsElement.style.width = w + 'px'
-    recentElement.style.opacity = tipsElement.style.opacity = '';
+    recentElement.style.opacity = tipsElement.style.opacity =
+        recentElement.style.WebkitMarginStart = '';
     spacer.style.width = spacing + 'px';
   } else if (recentShown) {
     recentElement.style.width = totalWidth + 'px';
-    recentElement.style.opacity = '';
+    recentElement.style.opacity = recentElement.style.WebkitMarginStart = '';
     tipsElement.style.width =
         tipsElement.style.opacity = 0;
     spacer.style.width = 0;
+
   } else if (tipsShown) {
     tipsElement.style.width = totalWidth + 'px';
     tipsElement.style.opacity = '';
     recentElement.style.width = recentElement.style.opacity = 0;
+    recentElement.style.WebkitMarginStart = '-2px';
     spacer.style.width = 0;
   }
 }
 
 /**
  * Returns the text used for a recently closed window.
  * @param {number} numTabs Number of tabs in the window.
  * @return {string} The text to use.
  */
 function formatTabsText(numTabs) {
@@ skipping 680 matching lines @@
     el.addEventListener('dragover', bind(this.handleDragOver, this));
     el.addEventListener('dragleave', bind(this.handleDragLeave, this));
     el.addEventListener('drop', bind(this.handleDrop, this));
     el.addEventListener('dragend', bind(this.handleDragEnd, this));
     el.addEventListener('drag', bind(this.handleDrag, this));
     el.addEventListener('mousedown', bind(this.handleMouseDown, this));
   }
 };
 
 dnd.init();