Use actual client width of list excluding scroll bar for adjusting column widths.

ui/webui/resources/js/cr/ui/table.js

Index: ui/webui/resources/js/cr/ui/table.js
diff --git a/ui/webui/resources/js/cr/ui/table.js b/ui/webui/resources/js/cr/ui/table.js
index 9e28e4c752e2361270ae2a7e037db70ffea79ea0..b5f0d45df7327b2dfe914d09d9b6b0043d45fb54 100644
--- a/ui/webui/resources/js/cr/ui/table.js
+++ b/ui/webui/resources/js/cr/ui/table.js
@@ -186,6 +186,13 @@ cr.define('cr.ui', function() {
 
       this.addEventListener('focus', this.handleElementFocus_, true);
       this.addEventListener('blur', this.handleElementBlur_, true);
+      this.list_.setClientWidthChangedCallback(
+          this.onListClientWidthChanged.bind(this));
+    },
+
+    onListClientWidthChanged: function(newClientWidth) {
+      this.normalizeColumns();
+      this.list_.redraw();
     },
 
     /**
@@ -361,7 +368,9 @@ cr.define('cr.ui', function() {
     },
 
     normalizeColumns: function() {
-      this.columnModel.normalizeWidths(this.clientWidth);
+      // list_.clientWidth must be used here instead of this.clientWidth,
+      // because it can be narrower by the thickness of the vertical scrollbar.
+      this.columnModel.normalizeWidths(this.list_.clientWidth);
     }
   };