Update Polymer from 1.1.4 -> 1.1.5

third_party/polymer/v1_0/components-chromium/iron-list/README.md

 iron-list
 ========================
 
 `iron-list` displays a virtual, *'infinite'* list. The template inside
 the iron-list element represents the DOM to create for each list item.
 The `items` property specifies an array of list item data.
 
 For performance reasons, not every item in the list is rendered at once;
 instead a small subset of actual template elements *(enough to fill the viewport)*
 are rendered and reused as the user scrolls. As such, it is important that all
@@ skipping 47 matching lines @@
       <div>
         Name: <span>[[item.name]]</span>
       </div>
     </template>
   </iron-list>
 </template>
 ```
 
 ### Resizing
 
-`iron-list` lays out the items when it recives a notification via the `resize` event.
+`iron-list` lays out the items when it recives a notification via the `iron-resize` event.
 This event is fired by any element that implements `IronResizableBehavior`.
 
 By default, elements such as `iron-pages`, `paper-tabs` or `paper-dialog` will trigger
 this event automatically. If you hide the list manually (e.g. you use `display: none`)
 you might want to implement `IronResizableBehavior` or fire this event manually right 
 after the list became visible again. e.g.
 
 ```js
-document.querySelector('iron-list').fire('resize');
+document.querySelector('iron-list').fire('iron-resize');
+```
+
+### Styling
+
+Use the `--iron-list-items-container` mixin to style the container of items, e.g.
+
+```css
+iron-list {
+ --iron-list-items-container: {
+    margin: auto;
+  };
+}
 ```
 
 ### When should `<iron-list>` be used?
 
 `iron-list` should be used when a page has significantly more DOM nodes than the ones visible on the screen. e.g. the page has 500 nodes, but only 20 are visible at the time. This is why we refer to it as a `virtual` list. In this case, a `dom-repeat` will still create 500 nodes which could slow down the web app, but `iron-list` will only create 20.
 
 However, having an `iron-list` does not mean that you can load all the data at once. Say, you have a million records in the database, you want to split the data into pages so you can bring a page at the time. The page could contain 500 items, and iron-list will only render 20.