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

chrome/browser/resources/new_new_tab.js

Index: chrome/browser/resources/new_new_tab.js
===================================================================
--- chrome/browser/resources/new_new_tab.js	(revision 21869)
+++ chrome/browser/resources/new_new_tab.js	(working copy)
@@ -696,21 +696,26 @@
     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;
   }
 }