MD History: Use one-way binding for history query state.

chrome/test/data/webui/md_history/test_util.js

Index: chrome/test/data/webui/md_history/test_util.js
diff --git a/chrome/test/data/webui/md_history/test_util.js b/chrome/test/data/webui/md_history/test_util.js
index b09085d595daf778326bc299c7fc8f2fb187bfd8..7e781fc28ee783b258b5a067f7083cf18951f49a 100644
--- a/chrome/test/data/webui/md_history/test_util.js
+++ b/chrome/test/data/webui/md_history/test_util.js
@@ -10,13 +10,13 @@
 function replaceBody(element) {
   var body = document.body;
   var app = body.querySelector('history-app');
-  // Clear the query on the app, if it exists. This clears any query in the URL.
-  if (app)
-    app.set('queryState_.searchTerm', '');
 
   var currentBody = app || body.querySelector('.test-body');
   body.removeChild(currentBody);
 
+  // Clear any query in the URL.
+  window.history.replaceState({}, '', '/');
+
   element.classList.add('test-body');
   body.appendChild(element);
 }