Print Preview: Fix manage link

If the "No destinations" message was visible in the recent destinations
list, the iron-list containing the destinations was pushed down and
extended invisibly over the "Manage" link for the print destinations,
preventing the link from working.

Fix this by ensuring that the iron-lists are the correct height: height
of the parent - height of parent's header line - height of "No
destinations" message (if showing).

Bug: 868274
Change-Id: Idf574923d69ae1c0ff1265efe62b9cc67b70af11
Reviewed-on: https://chromium-review.googlesource.com/1153430
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579306}

chrome/browser/resources/print_preview/new/destination_list.html

@@ -20,10 +20,6 @@
         user-select: none;
       }
 
-      :host #list {
-        height: 100%;
-      }
-
       :host > header {
         background-color: transparent;
         border-bottom: 1px solid #d2d2d2;

chrome/browser/resources/print_preview/new/destination_list.js

@@ -41,6 +41,7 @@ Polymer({
     hasDestinations_: {
       type: Boolean,
       value: true,
+      observer: 'hasDestinationsChanged_',
     },
 
     /** @private {boolean} */
@@ -116,5 +117,12 @@ Polymer({
   onDestinationSelected_: function(e) {
     this.fire('destination-selected', e.target);
   },
+
+  /** @private */
+  hasDestinationsChanged_: function() {
+    // If there are no destinations, leave space for "no destinations" message.
+    this.$.list.style.height = this.hasDestinations_ ?
+        'calc(100% - 1rem - 9px)' : 'calc(100% - 2rem - 9px)';
+  },
 });
 })();