[MD History] Add history-searched-label to embolden the synced device search.

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

Index: chrome/test/data/webui/md_history/history_list_test.js
diff --git a/chrome/test/data/webui/md_history/history_list_test.js b/chrome/test/data/webui/md_history/history_list_test.js
index dc9f24b15abc2173d616325851fbcf709ae71309..82f96314086fff1c004933310474523d307e66ce 100644
--- a/chrome/test/data/webui/md_history/history_list_test.js
+++ b/chrome/test/data/webui/md_history/history_list_test.js
@@ -142,7 +142,9 @@ cr.define('md_history.history_list_test', function() {
           assertTrue(index != -1);
 
           // Check that the search term is bolded correctly in the history-item.
-          assertGT(title.innerHTML.indexOf('<b>google</b>'), -1);
+          assertGT(
+              title.children[0].$.container.innerHTML.indexOf('<b>google</b>'),
+              -1);
         });
       });