Remove app name from File.app's window.

As a part of Files.app's re-design, app name should be gone.

BUG=402344
TEST=none

Review URL: https://codereview.chromium.org/862263002

Cr-Commit-Position: refs/heads/master@{#312575}

ui/file_manager/file_manager/foreground/css/file_manager.css

@@ -144,18 +144,6 @@ a:focus {
   width: 190px;
 }
 
-.dialog-navigation-list-header {
-  flex: none;
-  height: 48px;  /* Keep in sync with #dialog-header. */
-  line-height: 45px;
-}
-
-.dialog-navigation-list-header #app-name {
-  color: #303030;
-  font-size: 130%;
-  margin: 0 15px;
-}
-
 .dialog-navigation-list-contents {
   display: flex;
   flex: 1 1 auto;

ui/file_manager/file_manager/foreground/js/ui/file_manager_ui.js

@@ -233,8 +233,6 @@ function FileManagerUI(element, launchParam) {
       this.dialogType_, /** @type {!Document} */(this.element.ownerDocument));
 
   // Initialize attributes.
-  this.element.querySelector('#app-name').innerText =
-      chrome.runtime.getManifest().name;
   this.element.setAttribute('type', this.dialogType_);
 
   // Modify UI default behavior.

ui/file_manager/file_manager/main.html

@@ -302,9 +302,6 @@
 
     <div class="dialog-container">
       <div class="dialog-navigation-list">
-        <div class="dialog-navigation-list-header">
-          <span id="app-name"></span>
-        </div>
         <div class="dialog-navigation-list-contents">
           <tree id="directory-tree" tabindex="15"></tree>
         </div>