Make sure the PDF material toolbar gets hidden after loading.

chrome/browser/resources/pdf/ui_manager.js

Index: chrome/browser/resources/pdf/ui_manager.js
diff --git a/chrome/browser/resources/pdf/ui_manager.js b/chrome/browser/resources/pdf/ui_manager.js
index 53bb72010c0e9be5fc8afa9c4abe6fcc43105f55..31401d0fecc69786014d46c25705bc4969b576ab 100644
--- a/chrome/browser/resources/pdf/ui_manager.js
+++ b/chrome/browser/resources/pdf/ui_manager.js
@@ -22,7 +22,7 @@ function UiManager(window, toolbar, panes) {
 
   var userInputs = ['click', 'keydown', 'mousemove', 'scroll'];
   for (var i = 0; i < userInputs.length; i++)
-    this.window_.addEventListener(userInputs[i], this.showUi_.bind(this));
+    this.window_.addEventListener(userInputs[i], this.showUi.bind(this));
 }
 
 UiManager.prototype = {
@@ -30,7 +30,7 @@ UiManager.prototype = {
    * @private
    * Display the toolbar and any pane that was previously opened.
    */
-  showUi_: function() {
+  showUi: function() {
     this.toolbar_.show();
     for (var i = 0; i < this.panes_.length; i++)
       this.panes_[i].showIfOpenedByUser();