MD WebUI: Add shared cr-toolbar element

chrome/browser/resources/md_history/history_toolbar.js

Index: chrome/browser/resources/md_history/history_toolbar.js
diff --git a/chrome/browser/resources/md_history/history_toolbar.js b/chrome/browser/resources/md_history/history_toolbar.js
index d5341869f89648bc91a27d855b519a186de672f9..798a3c9fc7c2a811654b8ccdd742bd614452ecd6 100644
--- a/chrome/browser/resources/md_history/history_toolbar.js
+++ b/chrome/browser/resources/md_history/history_toolbar.js
@@ -87,9 +87,9 @@ Polymer({
     if (this.searchTerm == search)
       return;
     this.searchTerm = search;
-    var searchField = /** @type {SearchField} */(this.$['search-input']);
-    searchField.showAndFocus().then(function(showing) {
-      if (showing) searchField.setValue(search);
+    var toolbar = /** @type {CrToolbarElement} */(this.$['main-toolbar']);

[dpapad, 2016/05/18 23:39:13]

Is toolbar expected to be null after this line? If not this should be
@type {!CrToolbarElement}

Also nit: How about changing the ID name to mainToolbar, so that you can
reference it easier from JS, like
this.$.mainToolbar

[tsergeant, 2016/05/19 07:11:55]

Closure comment: Done.

Ack on the comment about renaming the ID. We're still using kebab-case
everywhere else in history and haven't decided whether to switch to camelCase
yet, so I'd rather just stay consistent for now.

+    toolbar.showAndFocus().then(function(showing) {
+      if (showing) toolbar.setValue(search);
     });
   },
 
@@ -105,7 +105,7 @@ Polymer({
 
   attached: function() {
     this.searchFieldDelegate_ = new ToolbarSearchFieldDelegate(this);
-    /** @type {SearchField} */(this.$['search-input'])
+    /** @type {CrToolbarElement} */(this.$['main-toolbar'])

[dpapad, 2016/05/18 23:39:13]

Nit: !CrToolbarElement

[tsergeant, 2016/05/19 07:11:55]

Done.

         .setDelegate(this.searchFieldDelegate_);
   },