PolymerTest.clearBody: don't remove vulcanized styles

chrome/test/data/webui/polymer_browser_test_base.js

Index: chrome/test/data/webui/polymer_browser_test_base.js
diff --git a/chrome/test/data/webui/polymer_browser_test_base.js b/chrome/test/data/webui/polymer_browser_test_base.js
index b63110cd36f562c154c2028349724d90f5e5038f..40bd809b0d621122a52d9e91972aae14328477cb 100644
--- a/chrome/test/data/webui/polymer_browser_test_base.js
+++ b/chrome/test/data/webui/polymer_browser_test_base.js
@@ -188,10 +188,24 @@ PolymerTest.loadScript = function(src) {
 };
 
 /**
- * Removes all content from the body.
+ * Removes all content from the body, save for the global <style> elements
+ * used by a vulcanized build.
  */
 PolymerTest.clearBody = function() {
-  document.body.innerHTML = '';
+  var vulcanizeDiv = document.querySelector('body > div[hidden][by-vulcanize]');

[dpapad, 2017/04/24 18:35:15]

Would it be simpler to do the following?

var toRemove = document.body.querySelectorAll('[hidden][by-vulcanize]
:not(style)');
// iterate toRemove and call remove()

[dpapad, 2017/04/25 01:11:09]

Or maybe even better to use the following selector: '[hidden][by-vulcanize] >
:not(style)'

+  document.body.innerHTML='';
+  if (!vulcanizeDiv)
+    return;
+
+  if (!vulcanizeDiv.hasAttribute('processed-by-test')) {

[dpapad, 2017/04/24 18:35:15]

What is "processed-by-test"?

+    for (var child of vulcanizeDiv.children) {
+      if (child.tagName != 'STYLE')
+        child.remove();
+    }
+    vulcanizeDiv.setAttribute('processed-by-test', '');
+  }
+
+  document.body.appendChild(vulcanizeDiv);
 };
 
 /**