[polymer] Switches .appendChild() to Polymer.dom()...appendChild()

tracing/tracing/ui/base/dropdown_test.html

Index: tracing/tracing/ui/base/dropdown_test.html
diff --git a/tracing/tracing/ui/base/dropdown_test.html b/tracing/tracing/ui/base/dropdown_test.html
index 8801a927a1f8eaefd8a4264e4eb34068daa11a99..c975ae197a8b1330b93cecae7e14077a8beb7f61 100644
--- a/tracing/tracing/ui/base/dropdown_test.html
+++ b/tracing/tracing/ui/base/dropdown_test.html
@@ -18,16 +18,21 @@ tr.b.unittest.testSuite(function() {
     dd.style.width = '50px';
     dd.iconElement.textContent = 'Settings ' + String.fromCharCode(0x2699);
 
-    dd.appendChild(tr.ui.b.createDiv({textContent: 'item 1'}));
-    dd.appendChild(tr.ui.b.createDiv({textContent: 'item 2 longer'}));
-    dd.appendChild(tr.ui.b.createDiv({textContent: 'item 3'}));
+    Polymer.dom(dd).appendChild(tr.ui.b.createDiv({textContent: 'item 1'}));
+    Polymer.dom(dd).appendChild(
+        tr.ui.b.createDiv({textContent: 'item 2 longer'}));
+    Polymer.dom(dd).appendChild(
+        tr.ui.b.createDiv({textContent: 'item 3'}));
 
     var container = tr.ui.b.createDiv();
     container.style.height = '100px';
-    container.appendChild(dd);
-    container.appendChild(tr.ui.b.createDiv({textContent: 'some text'}));
-    container.appendChild(tr.ui.b.createDiv({textContent: 'some more text'}));
-    container.appendChild(tr.ui.b.createDiv({textContent: 'more text'}));
+    Polymer.dom(container).appendChild(dd);
+    Polymer.dom(container).appendChild(
+        tr.ui.b.createDiv({textContent: 'some text'}));
+    Polymer.dom(container).appendChild(
+        tr.ui.b.createDiv({textContent: 'some more text'}));
+    Polymer.dom(container).appendChild(
+        tr.ui.b.createDiv({textContent: 'more text'}));
     this.addHTMLOutput(container);
 
     dd.show();